Copyright: Internet Software Solutions
Citation: Copyright 1997-1198  Internet Software Solutions


Overview

The Secure Mail System Overview

Secure Mail is a simple to use but feature rich e-mail program that will allow you to send and receive e-mail and file attachments via your local Internet connection. Some of the many features provided are: Installation of the strongest e-mail and file attachment encryption, authentication of sender, e-mail tampering warning, a word processor with spell check and thesaurus, Mime or uuencode selection (e-mail encoding type), message priority selection , multiple accounts, message filtering, direct image scanning, audio mail, and more. Secure Mail was designed to be the most secure and easy way of sending information from point A to point B.

Secure Mail uses PGP 2.62, a DOS based encryption program that is arguably the best one around. It is awkward and time consuming to use even if you are very familiar with the DOS system environment. Secure Mail installs, manages, and utilizes PGP and all its features so that you can have the best encryption available without becoming a programmer to do it. Sending encrypted e-mail information is truly a single click affair allowing you to get on and off your system as quickly as possible, the program works for you and not the other way around. You will know if incoming messages are encrypted by visual icons, a lock will appear next to the message to indicate that the message is encrypted or signed. If you can compose a letter and hit the send button, then you can send encrypted mail information.


What is PGP

Pretty Good(tm) Privacy (PGP), from Phil's Pretty Good Software, is a high security cryptographic software application for MSDOS, UNIX, VAX/VMS, and other computers.  PGP allows people to exchange files or messages with privacy, authentication, and convenience.  Privacy means that only those intended to receive a message can read it. Authentication means that messages that appear to be from a particular person can only have originated from that person. Convenience means that privacy and authentication are provided without the hassles of managing keys associated with conventional cryptographic software.  No secure channels are needed to exchange keys between users, which makes PGP much easier to use.  This is because PGP is based on a powerful new technology called "public key" cryptography.

PGP combines the convenience of the Rivest-Shamir-Adleman (RSA) public key cryptosystem with the speed of conventional cryptography, message digests for digital signatures, data compression before encryption, good ergonomic design, and sophisticated key management.

And PGP performs the public-key functions faster than most other software implementations.  PGP is public key cryptography for the masses.


Composition Setup

The composition tab is used for default settings when you compose a new e-mail message.

Encoding:

You have two selections in this area, Mime and UUEncode. E-mail is sent using either type of encoding to best facilitate speedy transfers, The Mime option is best to use and is most compatible with the new mail programs. The UUEncode is mostly used for backward compatibility with some of the older mail programs or services.  (E.g. At the time of this writing, the Microsoft Exchange Mailer did not work with Mime. The idea here is to be able to choose either type of encoding depending on the recipient’s type of decoding. If the recipient can only UUEncode , they should be able to read your e-mail and run your file attachments without problems.

Character Set:

This property will be useful for European users. Default this property is set to USA ASCII, if you wish to use high ASCII characters (ASCII>128) in your message body, you should set the Character Set option to SO8859.

Mail Directory:

This is the location where all your Message Folder/Directories will be created. The default directory is the directory you selected to install The Secure Mail System plus the currently logged on user name. Use the Browse button to select an alternate directory. Basically this is where your mail goes.

Forwarding Incoming Messages:

This function forwards your e-mail to an address that you choose. When a valid e-mail address has been entered in the edit box for forwarding, all incoming e-mail will be automatically forwarded to this e-mail address. To stop forwarding the e-mail, clear out the forwarding address from the edit box. This might be useful if you have the scheduler on to pick up your e-mail while you are away, then the e-mail could be sent to an address at your present location say at your relatives house, who have a local e-mail address.

Forwarding Outgoing Messages:

When a valid e-mail address has been entered in the edit box for forwarding outgoing, then a copy of all outgoing e-mail will be automatically sent to this e-mail address. To stop copying the e-mail, clear out the address from the edit box. This might be useful if you wish to send a copy of all correspondence to another person, say your lawyer or business partners.

See Setup for other setup options.


Secure Mail Options

The Options Tab of the setup screen allows you to select option that can be active or inactive. There are two categories, User Options, and Prompts. The User Options effect how The Secure Mail System operates while the Prompts allows you to turn off a warning prompt. The following items are available on the Options Tab.

User Options:

Check Spelling:

When this option is checked, the spell check will be run automatically  when you send a 	 message. This function in enabled if you installed the spell check file during the install process. The spell check utilizes your choice of dictionaries and will help you check your e-mail for spelling errors. It is very easy to use and you can even add your own words.

Quote Messages:

When this option is checked and you hit ‘reply to a message’ you will be writing within the message text of the e-mail that you just received. This enables you to reply with in the senders text and send both yours and their e-mail in its entirely back to the sender...this eliminates confusion as to what people are talking about when replying to queries and such...without this option checked you will reply to the sender in your own blank message composition window.

Delete Trash On Exit:

This option will delete the files in your Trash Folder when the application terminates. This is useful in keeping your Trash Folder from being to clustered.

Default to Plain Text:

If you choose to disable colors, fonts, sizes and body formatting then you can choose the default to plain text option. As stated just above you will eliminate the additional ‘font file’ attached to your e-mail and all your e-mail will be in the standard black text. If you typically send to users who are receiving allot of indecipherable text after the readable text then it might be because their e-mail program cannot  decode  the ‘font file’ attached to your message. Just enable the default to plain text option and they will receive only the default black text and no file which has the additional information regarding fonts, colors ect.

Keep Copies Of Sent Mail:

When this option is checked, all sent mail will be moved to your Sent Mail Folder. If unchecked, all sent mail will be deleted.

Word Wrap:

When this option is checked, all text in the message editor will be warped to the next when the text reaches the boundaries of the message editor.

Tabs In Body:

When this options is checked, Tab Characters will be allowed in the message body. Whoever when this option is checked, you will be able to tab into the message editor screen but not be able to tab out of it.

Press OK:

When this option is checked, when a non-critical message is displayed, you can set a delay time when the OK button is automatically is pressed.

Prompts:

Delete Message:

When this option is checked, you will be prompted when you delete messages or your empty your Trash Folder.

Delete Unread Mail:

When this option is checked, you will be warned if you are attempting to delete a message you have not read yet.

Delete Unsent Mail:

When this option is checked, you will be warned if your are attempting to delete messages that have not been sent yet.

No Subject In Message:

When this option is checked, you will be warned if your are attempting to send a message that contains no subject matter.

Empty Message Body:

When this option is checked, you will be warned if your are attempting to send a message that contains no text in the message body.

Show Unread Messages At Startup:

When this option is checked, a information box will be displayed at program startup, showing the number of unread messages in your In Box.

Exit With Unsent Mail:

When this option is checked, you will be warned if your are attempting to exit The Secure Mail System when messages are still in your Out Box waiting to be sent.

Exit Prompt:

When this option is checked, you will be warned if your are attempting to exit The Secure Mail System.

See Setup for other setup options.


Password Setup

Use the password option to protect sensitive areas of the mailer. You must enter your password correctly twice and enable the password protection by checking Enable Password Checking. Use caution because once the password has been set, you will not be able to access the password tab without having to enter the current password. The following areas can be password protected. A password will be asked when.....

•	At Startup 	       -  Secure Mail first runs.

•	On Exit	       -  Secure Mail is shut down.

•	Mailer Setup     -  Mailer Setup is selected from the main menu.

•	PGP Setup        -  PGP Setup is selected from the main menu.

•	PGP Key Menu - Opening this menu.

•	Mail Transfers  - Dialing to your service provider.

•	Read Mail         - Reading your messages.

Do not lose your Password! The Secure Mail System has no back door into any portion of its programming. We did this so that people knew they had the most secure and uncompromised program available. Create passwords that can not be easily figured out, that only you know and are well hidden if you write them down. If you lose your password then you will have to uninstall The Secure Mail System and then reinstall it.

The reason of so much password protection embedded in The Secure Mail System is to allow as much or as little security as you wish...as multiple users can use a single computer and with certain areas like the PGP/Mailer setup protected you can be reasonably sure that your keys and configuration files are protected from tampering.

See Setup for other setup options.


Message Menu Item

This menu item will only become accessible when a message has been selected in the Message List Box. You can also right click your mouse on a message to bring up the Pop Up version of this menu. The following items can be found on this menu item.

Mark As Read:

This will mark all selected message as read. To tell if a message has been read, there will be a open envelope or a open lock if the message has some type of encryption, next to the message. You can select more then one message by holding down the Shift Key for groups or the Ctrl Key if you want to select individual messages;

Mark As  Unread:

This will mark all selected message as unread. To tell if a message has been unread, there will be a closed envelope or a closed lock if the message has some type of encryption, next to the message. You can select more then one message by holding down the Shift Key for groups or the Ctrl Key if you want to select individual messages;

Read Message:

Selecting this option will allow you to view the selected message in the message editor. This option is also available by double clicking the message you would like to read with your left mouse button.  See Reading Message for more information on this topic.

NOTE: If you have your password enabled for this option, you will have to enter your password before your are allowed to read your message.

Delete Message:

Selecting this option will delete the selected messages from a folder, they will initially be moved to the Trash Folder.  If you are deleting messages from the Trash Folder, they will be permanently deleted. This allows you to be able to recover accidentally deleted messages from the Trash Folder. To delete a message, click on the message to be deleted, then drag and drop the message on the Trash Folder. (Name) The second way is to highlight the message that you want to deleted and then select Delete from the Message Menu. You can delete more then one message by doing a group select. To do a group select, hold down the SHIFT (Block Select) or CTRL (Individual Select) keys and click on the messages you want to delete, then use one of the above methods to finish the delete procedure.

View Message Header:

Selecting this option will allow you to view the Internet Message Header of the selected message. Viewing this header can tell you where the message has been and for how long. Useful for tracing messages.


PGP Key Management

PGP Menu Item

This menu item is used to access your PGP Setup and Key Manager.

Key Manager:

This will run the PGP Key Manager. The Key Manager is described in detail in the PGP Key Management area of Using PGP with The Secure Mail System.

PGP Settings:

This menu item is used to edit your PGP Settings. See PGP Setup for more information on the PGP settings that are available.


Help Menu Item

This is where you can find the help topic menu. You can also highlight a item that you need help with and press F1 to bring up the topic for the selected item.


Folders & Messages

Folders are used to organize your messages in a clean manner. This allows you quick access to certain messages without having to hunt through hundreds of messages. The first five folders are used by The Secure Mail System to manage your messages, however it is up to you to move the messages into the proper folder for saving or deleting.

Moving messages is quite simple, you can select one or many messages and drag then drop then on the folder you would like to place the selected messages in. To drag and drop do the following.

1) You must click on the sender name and highlight it.  If you want to select more then one message, hold down the shift (Block Select) or Ctrl (Individual Select) key and select all the messages you would like to move.

2) Once all the messages have been selected, move your mouse to one of the selected messages and click and hold your left mouse button down.

3) Drag the mouse over to the FOLDER NAME you want the messages in.

4) Release the left mouse button.

If you are deleting message from your folder, they will be moved to your trash can first. This gives you a safety cushion in case you had inadvertently deleted a message you did not want to. This only holds true if you are not deleting message in the Trash Folder. To empty the trash folder, select Empty Trash from the File Menu or by selecting files as stated above and then deleting them from the Message Menu or by clicking on the Trash Can icon on the Icon Bar.

Related Topics:

Folder Menu

Message Menu


Message List Box Overview

The message list box contains a listing of all messages in the selected folder and their status as if they have been read or not. By right clicking your mouse button while the mouse is in the Message List Box area, will pop up the Message Menu. You will find the newest messages at the top of the list.

Header Information:

The following information is displayed for each message in the Message List Box.

1) Sender’s Name or E-Mail Address - Who the message was from.

2) Subject Matter - What the message is about (if entered)

3) Date & Time - The Date and Time the message was sent.

Reading Messages:

To read a message you can double click on the message senders name to read the selected message or select the message you want to read by highlighting the senders name then selecting Read from the Message Menu.

NOTE: If you have protected the read message option with a password, you must enter the password every time you select a new message to read. To avoid this, select the first message to read and enter your password (if password protected), then use the Prev. and Next buttons to navigate through the messages. This will eliminate the need for you to enter your password every time to read the next message.

Deleting Messages:

When deleting messages from a folder, they will initially be moved to the Trash Folder.  If you are deleting messages from the Trash Folder, they will be permanently deleted. This allows you to be able to recover accidentally deleted messages from the Trash Folder. To delete a message, click on the message to be deleted, then drag and drop the message on the Trash Folder. (Name) The second way is to highlight the message that you want to deleted and then select Delete from the Message Menu. You can delete more then one message by doing a group select. To do a group select, hold down the SHIFT (Block Select) or CTRL (Individual Select) keys and click on the messages you want to delete, then use one of the above methods to finish the delete procedure.

Related Topics:

Message Menu

Folder Menu

Message Icons


Status Bar Overview

The status bar is located at the bottom of The Secure Mail Systems window. The status bar contains information about the status of The Secure Mail System. Their are five panels that are used for this. They are listed below from left to right.

Date & Time:

This is the current date and time.

In:

This panel contains information about your In Box. The first number indicates the number of messages that are contained in your In Box. The second number indicates the number of messages you have read.

Out:

This panel contains information about your Out Box. This number indicates the number of messages that are waiting to be sent to your server.

Transfer State:

This panel indicates what state the transfer mode is in. It also shows connection progress. If an error occurred during the transfer, it will also be displayed here.

Progress Indicator:

A bar graph that indicates the progress of large mail transfers.

Related Topics:

Folders

Call Server


Message Menu

Composition Message Menu Item

This menu is used for message related operations. Some of the more frequently used items can also be found on the Composition Icon Bar. The following items can be selected from this menu.

Send:

This will validate your message (Check to make sure all necessary fields have correct data), then it will spell check the message (Default Enabled), it will then add your Signature File if you have chosen one in the Mailer Setup under the Identity Tab,  then store the message in the Out Box for delivery.

Note: This Item will not become available until a recipients e-mail address has been specified.

Default Sign & Send:

This item does the same as the Send and will also sign the message with your PGP Signature. This is useful for tamper protection and validity of a message. The Default Signature is used for this and can be set in the PGP Setup under the Advanced Options Tab.

Note: This item is only available if PGP has been installed.

Default Encrypt & Send:

This item does the same as the Send and will also Encrypt the message with the recipients PGP Public Key. This is useful for tamper protection and unauthorized access to the message. The Default Encryption is used for this and can be set in the PGP Setup under the Advanced Options Tab.

Note: This item is only available if PGP has been installed.

Save Draft Copy:

This will save the message in the Draft Folder for later completion. This is useful if you need to  a long letter at a later time or using the same letter for different reasons.

Add Contact To Address Book:

This will allow you to add the current messages sender to your Address Book. This will automatically add the sender name and e-mail address for you then show the Contact Form so that you can add additional information about this contact.

New Message:

This will discard the current message you are writing or if you are reading a message, it will bring up a new message window.

Reply To Message:

This is used for replying to the current message you are viewing. A new message composition screen will be created with the recipient’s address already filled in. If you have chosen to Quote the original message (See Composition Tab in Mailer Setup), it will be appended to your new message. This aids in keeping on track of the conversation.

Forward This Message:

This will allow you to pass the current message on to another person. This is useful if you receive a message that does not really pertain to you but know the person that it does.

Attach A File:

This allows you to attach one or more files to the current message. This will bring up a dialog box so you can select the file or files that you want to attach.

Load A Document:

Loads a RTF or TXT document into the Message Window.

Discard This Message:

This will send the current message to the Trash Folder.

View Message Header:

Selecting this option will allow you to view the Internet Message Header of the selected message. Viewing this header can tell you where the message has been and for how long. Useful for tracing messages.

Next Message:

This option allows you to view the next message in the Message List Box.

Previous Message:

This option allows you to view the previous message in the Message List Box.

Discard & Get Next Message:

This option allows you to discard the current message and view the next message in the Message List Box.

Discard & Get Previous Message:

This option allows you to discard the current message and view the previous message in the Message List Box.

Hide Return Path:

Use this option if you don’t want the recipient to know whom the message came from. This will show anonymous@unknown.com in the FROM field of the message.

Print:

This prints the current message on your printer.

Exit:

Closes the composition screen.


PGP Message Menu

Composition PGP Message Menu

This menu is used to manually create or manipulate PGP Messages. You must have PGP installed before this menu item is available. The following items are available from this menu.

Sign Msg.

Attached Signature:

If you want to send a signed message as E-mail and want to makes it possible for the recipient to read the signed message with human eyes, without the aid of PGP, and the original plain text message is in text (not binary) form, Use this option. This will send the message through an E-mail channel in such a way that the message text does not get compressed, and the ASCII armor is applied only to the binary signature certificate, but not to the message text. Of course, PGP is still needed to actually check the signature.

Detached Signature:

If you a sign a message as a detached signature, the original message is left intact but generates a separate file that hold the signature for that message. This allows for the recipient to read the message without having to decrypt the message first or detaching the signature to clean up the message. The Signature is automatically attached as a file attachment.

Encrypt:

Sign & Encrypt:

This produces a nested cipher text file. Your secret key is used to create the signature and is automatically looked up in your secret key ring via your userid.  The recipient’s public encryption key is automatically looked up in your public key ring via their User ID from the Address Book or by your manual selection.

Note: that PGP attempts to compress the plain text before encrypting it.

Encrypt Only:

This option only will encrypt your file or message without attaching a signature to it. The recipient’s public encryption key is automatically looked up in your public key ring via their User ID from the Address Book or by your manual selection.

Note: that PGP attempts to compress the plain text before encrypting it.

Decrypt:

Decrypt:

This option will decrypt the current message. If you are not the key holder of this message, you will get an error that the decrypted message was not found and then you will see a message box indicating that you are not the key holder of this message. If the message has been signed, a validity check will be done on the message to ensure that it has not been tampered with. If the message is in good standing you will receive a message indicating that you have a good signature.

NOTE: Sometime a server will strip off trailing spaces or lines, if this happens, you will get a bad signature warning.

Signature:

Verify Signature:

This will verify an Attached Signature to validate the authenticity of the message.


Composition Help Menu

Composition Help

This menu will allow quick access to the following help areas.

Reading Messages:

This will jump to the Reading Messages Help Area. This area will explain step by step procedures and option you have while reading your mail.

Composing Messages:

This will jump to the Composing Messages Help Area. This area will explain step by step procedures on how to compose your mail and the option that are available to you.

PGP Messages:

This will jump to the How To Use PGP Help Area. This area will explain step by step procedures on how to compose and read PGP Messages.


Address Button

Composition Address Button

Selecting this button will show your Address Book. From your address book you can select each recipient you wish to send this message to.


Addressing Type

This is a drop down list box that allows you to select the following address types.

TO:

A list of recipients’ of this message.  Probably you will be setting only one recipient, but if you wish to address the message to many people, you can set multiple addresses.

CC:

Carbon copy recipients of this message.  The names listed with the CC selection will be included in the outgoing message.

BCC:

Blind carbon copy recipients of this message. Blind copy recipients are almost the same as Carbon copy recipients (CC), only difference is the names listed in BCC will not appear in the message.  Hence if the message corresponds to the message which has been received, BCC list will be empty.


Composition E-Mail Address

Enter the recipient’s e-mail address here if you are not using the Address Book. This is a manual entry of the e-mail address. Enter the e-mail address and hit return, the address will be added to the Address Window. You can also type in a partial name and if the name is found in the currently selected Address Book, then the corresponding address will be entered.


Composition Address Window

Composition Addressing Window

The addressing window displays all the recipients of the current message. To delete a recipient, highlight the recipients name you wish to delete, then click the right mouse button.

Related Topics:

Address Button

Address Type

Composition E-Mail Address


Message Priority

The message priority is used for an indicator to indicate how important the message is. This will not deliver the message any faster, it just gives you a visual indication that the message should not be ignored or that the message is not important at all. Secure Mail would display a burning envelope or a burning lock to indicate that the message has a high priority. This option only works with mailers that have this feature.

Related Topics:

Message Icons


Message Encoding Type

There are two types of encoding they are Mime and UU Encode. Mime is the latest and more widely used now in the industry. The UU Encode was the first generation of encoding and some services still use it today. As of this writing MSN is one of them. If you want to send a message to a user that is using MSN and Microsoft Exchange, you would want to select UU Encode or the recipient will require a separate program to decode the Mime message. You can select your default encoding type in the Mailer Setup under the Composition Tab.


Return Receipt

The Return Receipt option allows you to get a message from the mailer demon stating that the message has arrived at the destination mail box. This does not mean that the recipient has read the message it just indicates that it is in his mail box waiting for delivery.


Composition Plain Text Check Box

Composition Plaint Text Check Box

When this option is checked. Only a plain text messages is sent. This will disable all message editor function like Fonts and Colors. This is useful if the recipient of the message has a e-mail program that can not recognize alternate file attachment and is receiving unreadable text.


Message Subject

The message subject line is useful for a quick reference as what the message is about. The Secure Mail System will add “<No Subject Stated>” if the Message Subject Line is left blank.


File Attachment Window

The File Attachment Window is where all the files that are attached or will be attached for the message are displayed. You can right click your mouse while the mouse cursor is inside of the File Attachment Window to display the File Attachment Menu. If you double click on a file attachments icon, The Secure Mail System will run the program or associated program for that attachment if the associated program is available.


Composing Mail

Compose E-Mail

1?	Click the compose E-Mail Icon or 'Compose E-Mail' under file on the menu bar.

2?	Click  the 'Address' button. Addresses are entered, deleted and edited in this area.

3?	Double click the address of your choice in the address window to enter it in the compose e- mail screen

1?	Enter the subject header of the message to be seen by the recipient...this is unencrypted. You can leave this blank if you choose.

1?	With the tab button or pointer, move the cursor to the message text area(the biggest field) and  enter your message. Choose your Encoding Type Mime/UUencode, Plain Text, and  Priority as appropriate.

2?	Right click  your mouse pointer in the File Attachments filed to add, zip ect file attachments to your e-mail message.

3?	Click the send, encrypt & send, or sign & send from the Icon Bar or associated command under 'Message' on the menu bar to load the e-mail into the Out Box.

Depending on the amount of information in the file attachment  and e-mail being sent/encrypted, this could take some time. Once done, the 'Compose E-Mail' screen will vanish and show the Main Screen with the e-mail message loaded into the Out Box the message is ready to be sent on the next mail transfer.


Reading Messages

1?	Click the appropriate folder in the Folder List Box to reveal its contents.

2?	Double click the e-mail header itself under the sender column. Depending on the size of the file attachment if any and the size of the e-mail and Auto Decrypt is on and it is a encrypted message this may take a while to load the information in the Message Viewer/Composition Screen.

3?	Read your e-mail if unencrypted, or choose decrypt from the PGP menu to decrypt the message if Auto Decrypt is not on.

4?	Right click within the file attachment field to show the File Attachment Menu if you have a file attachment. Double clicking on a file attachment will run the associated program. If the file attachment icon is a Key then the sender has sent you a public key that can be directly added to your public key by selecting the file attachment and then using the File Attachment Menu select add public key to key ring. Also if a lock is displayed then the sender has sent you an encrypted file attachment. Use the save encrypted file option from the File Attachment Menu to decrypt and save the file. NOTE: You must know what type of file it is when you save it.

5?	If you have more then one message you wish to read use the Next & Previous arrows.

6?	If you want to replay to a message, click on the Reply Icon or Choose ‘Reply To Message’ from the message menu. All function will apply as in composing a message. If message quoting is enabled, then a copy of the original message is appended to your message, this is useful in staying on track of what some is writing about.

1?	Exit when done.


Contacting Information

The following is information on how you can contact Internet Software Solutions.

Internet:

issonline@cybergs.com	For Sales Information

http://www.cybergs.com/~issonline	WWW Web Page

cybergs.com	MS Net Meeting

U.S. Postal:

Internet Software Solutions

249 S.35 Street

Springfield, Or 97478


Trouble Shooting Overview

This section is designed to aid you in resolving possible problems that could occur while running The Secure Mail System. If you encounter a problem that is not in this section, please send an e-mail issonline@cybergs.com. We will try to answer your questions promptly.

The following section are covered in this topic.

I/O Errors:

I/O Error 32IO_32

I/O Error 103IO_103

I/O Error 11002IO_11002

PGP Problems:

The Lock Mouse Cursor Stays On

PGP Not Decrypting or Encrypting


I/O Error 32

This error occurs if the system can not access a file. This error will manly occur to a message index file. If your computer locks up or was shut down improperly, you may damage one of the index files. This is easy to repair, follow one of the procedures below.

1?	Find the damaged index by selecting each of your Message Folders. When the error occurs, you have found the damaged folder.

2?	Click your right mouse button to display the Folder Menu.

1?	Select the Rebuild Index Menu Option. This should repair the damaged index file.

If the above method fails then you will have to manually delete the index file using explore or similar software. Follow the steps below on how to do this.

1?	Determine which folder is damaged as indicated above.

2?	Shut down The Secure Mail System

1?	Find the Secure Mail Directory with your Explore. The default location is c:\Program Files\ISS\Secure Mail.

2?	Their will be a subdirecory with the name you logged in with when you started windows. Choose this directory.

3?	In this directory find the subdirecory that matched the folder name that was damaged. Select this directory.

1?	Find the file called ‘msg.idx’ and delete it.

1?	Restart The Secure Mail System.


I/O Error 103

This error occurs when a disk write error happens. This is usually do to the disk being full or a damaged disk. If your disk is not full, you may want to run Scan Disk and Defrag or similar programs to check your disk.


I/O Error 11002

This error occurs when The Secure Mail System can not find a Authoritative Host. Make sure you have not been disconnected from your ISP or Network.


PGP Lock Mouse Cursor Stays On

This happens when pgp encountered an error and is waiting for the correct input from you. This can happen if the Pass Phrase you entered in the PGP Configuration dose not match the Pass Phrase you entered when you generated your keys. Another reason would be, if you have assigned a key to a e-mail recipient that no longer exists on your key ring. PGP would then cause an error and wait for you to enter the correct key or cancel the operation.

To fix this problem. Go to your task bar and there you will find a program running called PGP. Select this program and a DOS window will be displayed. PGP should have displayed the error that it encountered. Look at the error and then correct it in Secure Mail.

NOTE: If you cancel a PGP encryption operation because a  key does not exist, PGP will sign the messages making it appear to be encrypted. This will only hold true if you do not have the Readable Message option Checked in your PGP Configuration.


PGP Keys Not Found

This error occurs when The Secure Mail System can not locate your PGP Keys. If you have not generated your private and public keys yet, you will get this error. In this case, generate your keys by selecting PGP Key Man. Option from the Main Menu Bar. Then select Generate Keys. This problem could also occur if you have moved your keys or renamed them and did not change the information in your PGP Configuration. To fix this, Select Setup from the Main Menu Bar then select PGP Setup. Go to the Key Ring Information Tab. Using the browse button, find and select you keys. The default location of you keys is in the c:\pgp directory. The naming of the keys are as follows.

If you had a previous install of PGP and used the default key settings, the keys would be:

PubRing.pgp

SecRing.pgp

If you installed PGP with the Secure Mail System then the keys will be named using your Windows login name followed by sec or pub as an extension which indicates if this is the public key ring or private key ring:

Tim.pub

Tim.sec

Related Topics:

Generating Keys

 	Key Management Overview


PGP Can't Find User Key

PGP User Key Not Found

This may happen when there is no key information in the users address book or their may be extra characters in the name field of the address book.


PGP Not En/Decrypting

PGP Not Encrypting or Decrypting

This problem can be many things but below are some common mistakes when setting up PGP.

First, be sure you are using the correct pass phrase that you entered when you created your keys. The pass phrase is case sensitive and at time the CAPS LOCK may have gotten left on unknowingly. Also be sure your user name is correctly entered as well. You only need to enter the number of characters of your user name or ID to make it unique and PGP will then find it.

Be sure that PGP is finding the correct key rings. Normally Secure Mail will warn you if your key are not found, however at times there may be more the one set of keys and the wrong ones were selected. This might happen if multiple users are using The Secure Mail System. Use the Key Manager and view the key to make certain that they are your keys.

If all fails, got to your PGP Settings and enable PGP Trouble Shooter option. This will display all command line options that are sent to PGP and what the errors are when PGP has completed. This will give you an Idea of what may be wrong.


Your Identity

This is an important area, if this area is not completed correctly, you will not be able to send any e-mail. Please take the time to fill this area out correctly.

You’re Real Name or Handle:

This is the name that gets associated with your e-mail address. This name will be used instead of your e-mail address on mailers that allow this option. This aids in determining your identity if your e-mail name is a combination of numbers and letters as some services use. For example: if your name is Bob Smith but you choose to go by Heavy Dude, then Heavy Dude is what you enter.

Your E-Mail Name:

This is the name that is usually given to you by your Internet Service Provider. If your e-mail address was (mushin123@your_domain.com) then your e-mail name would be (mushin123). It is the name that is before the @ symbol.

Your Domain Name:

Your domain name comes after the @ symbol of your e-mail address. If your e-mail address is (mushin123@my_domain.com) then (my_domain.com) would be your domain name.

NOTE: Do not add the @ symbol as part of your domain name.

Signature File:

This file is a standard text file that can be attached to the end of your e-mails automatically giving information on other ways to contact you. If you enter a file in the signature edit box, this option will be enabled. To disable this option delete the file information from the edit box. For example, at the end of all your messages you wish to have a message that says: “Yours Truly Heavy Dude” this can be created and saved in your signature file and will automatically be placed at the end of your e-mail text when you send it. This save allot of time entering in the same address and phone numbers for example.

See Setup for other setup options.


Network Setup

Provider Data

This area is important. If you do not enter the correct POP3 and SMTP Server addresses, you will not be able to send or receive your e-mail messages.

 SMTP Server:

Server: This is the address to the server that you will be sending your mail to. You must obtain this address from your service provider. Address example: smtp.win.net

Port: This is the address that is used by your service provider to distinguish what type of 	service you are requesting. (Don’t worry about it) Your service provider will let you know 	if default number of 25 will be acceptable or not.

POP3 Server:

Server: This is the address of the server that you will be receiving your mail from. You must obtain this address form your service provider.  Address example: pop3.win.net

User name: This is you log on name that is generally the same as your e-mail name.

Example: joeblo@domain.com the user name is joeblo and would be entered as such.

Password: This is the password that is given to you by your service provider.

Port: This is the address that is used by your service provider to distinguish what type of 	service you are requesting. (Don’t worry about it) Your service provider will let you know 	if default number of 110 will be acceptable or not.

See Setup for other setup options.


Folders

List Box Folders Overview

The Folder List box contains all your system and private folders. The first five folders can not be deleted and are system folders. Private folders are shown by mail boxes and can be deleted and renamed at any time. Right clicking your mouse while the mouse cursor is in the Folder List Box will Pop Up the Folder Menu. See Folder Menu Item for more information on the folder menu.

There are five system folders and they are listed in order below.

In Box:	  	This is where all incoming mail will be stored.

Out Box:	This is where all out going will be stored.

Sent:	This is where message is moved after they have been sent to the Internet.

Trash:	This is where all deleted messages are stored until you empty the trashcan.

Draft:	This is where your draft messages are stored.

All folders including the ones you create are for storing messages in a clean and organized way. See Folders & Messages for more information on how they relate.

The mailbox will indicate if you have unread mail in a folder by have the mail flag up. If the mail flag is down, you either have no messages in this folder or all messages have been read. If the mailbox door is open, this indicates the selected folder.


Message Icons

There are several icons used to give you information about a message. The following is a list of icons used and their meaning as related to the message.

Closed Envelope: 	Unread message-No encryption.

Closed Envelope Hot:	Unread urgent message-No encryption.

Open Envelope:	Read message - No encryption.

Closed Lock:	Unread message-Some sort of encryption.

Closed Lock Hot:	Unread urgent message-Some sort of encryption.

Open Lock:	Read message-Some sort of encryption.

 	Closed Envelope w/Spkr:	Unread Audio Message.

Closed Envelope w/Spkr Hot:	Unread urgent Audio Message.

Open Envelope w/Spkr:	Read Audio Message.

Note: The closed lock is also used to indicate that a entry in the phone book has public key information.

Related Topics:

Message List Box Overview


Multiple Users

The Secure Mail System has the capability to have multiple user configurations. Each user will have a completely separate configuration system, which includes the PGP Key Rings as well. This option is an automatic function of The Secure Mail System and uses the Windows Logon option of Windows Networking. The Windows Networking will be installed when you install Dialup Networking.

When the logon screen appears select the user you wish to logon. The Secure Mail System will switch to the configurations for this user at startup.


License Agreement

Secure Mail Systems License Agreement

The Secure Mail System on your system for a limited 30-day trial period. After the trial period expires, The Secure Mail System has various restrictions. Please see Registering for more information. Once licensed by an authorized vendor, you may use The Secure Mail System on a single Computer system only. License numbers are not transferable without the express consent of the copyright holder.

THIS SOFTWARE AND ACCOMPANYING MATERIALS ARE DISTRIBUTED "AS IS"

WITHOUT WARRANTY, EXPRESS, IMPLIED OR STATUTORY, INCLUDING BUT

NOT LIMITED TO ANY IMPLIED WARRANTIES OF MERCHANTABILITY AND

FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL ANYONE

INVOLVED WITH THE CREATION AND PRODUCTION OF THIS PRODUCT BE

LIABLE FOR INDIRECT, SPECIAL, OR CONSEQUENTIAL DAMAGES, ARISING

OUT OF ANY USE THEREOF OR BREACH OF ANY WARRANTY. ONCE LICENSED,

ANY UNAUTHORIZED DISTRIBUTION OF THE LICENSE NUMBER WILL

IMMEDIATELY INVALIDATE YOUR LICENSE AND NO PRODUCT SUPPORT WILL

BE GIVEN. ILLEGALLY DISTRIBUTING A LICENSE NUMBER WILL ALSO BRING

ABOUT CRIMINAL CHARGES TO THE FULL EXTENT OF THE LAW.

Copyright Notices

The Secure Mail System Copyright (c) 1997 by Internet Software Solutions. All rights reserved.

RSA Cryptographic-RSA LABORATORIES

PGP Version 2.6.2 - 11 Oct 94 Software by Philip Zimmermann, and many others.

Windows is a trade of Microsoft Corporation


Registering The Secure Mail System

Run Registration Wizard

The Secure Mail System is not free. You have a 30-day evaluation period. After 30 days you must register The Secure Mail System. The Secure Mail System will enable various restrictions after 30 days.

Visit our web site at http://www.cybergs.com/~issonline/ordering.html for the latest pricing and ordering information.


Setup Notification Tab

The notification tab allows you to enable and disable notification dialogs and sounds.

Flash Bar On New Mail:

When enabled, the caption bar will flash and also the Secure Mail Icon will flash to indicate that new mail has arrived.

Show New Mail Dialog:

When selected, a dialog will appear to indicate how many new messages have arrived and how many of them have been filtered.

Show No New Mail Dialog:

When selected, a dialog will appear when the mailer has just checked mail and no new mail was found.

New Mail Pager Notification:

When selected, a page will be sent to your pager to indicate that new mail has arrived. You must have enabled the pager option for this option to be used. This option is only available in Secure Mail Pro.

On Start-up:

When selected, will play the WELCOME.WAV file when you first start Secure Mail.

On Exit:

When selected, will play the GOODBY.WAV file when you have selected to terminate the application.

On New Mail:

When selected will play the GOTMAIL.WAV file when new mail has arrived. If the GOTMAIL.WAV is not found, a system beep will be played instead. This will be repeated every 60 seconds.

On Critical Error:

When Selected, will play the FATELERR.WAV file when an irrecoverable error has occurred.


PGP Overview
Phil's Pretty Good Software

Presents

=======

PGP(tm)

=======

Pretty Good(tm) Privacy

Public Key Encryption for the Masses

--------------------------

PGP(tm) User's Guide

Volume I: Essential Topics

--------------------------

by Philip Zimmermann

Revised  11 October 94

PGP Version 2.6.2 - 11 Oct 94

Software by

Philip Zimmermann, and many others.

Synopsis:  PGP(tm) uses public-key encryption to protect E-mail and data files.  Communicate securely with people you've never met, with no secure channels needed for prior exchange of keys.  PGP is well featured and fast, with sophisticated key management, digital

signatures, data compression, and good ergonomic design.

Software and documentation (c) Copyright 1990-1994 Philip Zimmermann. All rights reserved.  For information on PGP licensing, distribution, copyrights, patents, trademarks, liability limitations, and export controls, see the "Legal Issues" section in the "PGP User's Guide, Volume II: Special Topics".  Distributed by the Massachusetts Institute of Technology.

"Whatever you do will be insignificant, but it is very important that you do it."  --Mahatma Gandhi

Quick Overview

 ==============

Pretty Good(tm) Privacy (PGP), from Phil's Pretty Good Software, is a high security cryptographic software application for MSDOS, Unix, VAX/VMS, and other computers.  PGP allows people to exchange files or messages with privacy, authentication, and convenience.  Privacy means that only those intended to receive a message can read it. Authentication means that messages that appear to be from a particular person can only have originated from that person. Convenience means that privacy and authentication are provided without the hassles of managing keys associated with conventional cryptographic software.  No secure channels are needed to exchange keys between users, which makes PGP much easier to use.  This is because PGP is based on a powerful new technology called "public key" cryptography.

PGP combines the convenience of the Rivest-Shamir-Adleman (RSA) public key cryptosystem with the speed of conventional cryptography, message digests for digital signatures, data compression before encryption, good ergonomic design, and sophisticated key management.

And PGP performs the public-key functions faster than most other software implementations.  PGP is public key cryptography for the masses.

PGP does not provide any built-in modem communications capability.  You must use a separate software product for that.

This document, "Volume I: Essential Topics", only explains the essential concepts for using PGP, and should be read by all PGP users.  "Volume II: Special Topics" covers the advanced features of PGP and other special topics, and may be read by more serious PGP users.  Neither volume explains the underlying technology details of cryptographic algorithms and data structures.


Why Do You Need PGP
Why Do You Need PGP?

====================

It's personal.  It's private.  And it's no one's business but yours. You may be planning a political campaign, discussing your taxes, or having an illicit affair.  Or you may be doing something that you feel shouldn't be illegal, but is.  Whatever it is, you don't want your private electronic mail (E-mail) or confidential documents read by anyone else.  There's nothing wrong with asserting your privacy.  Privacy is as apple-pie as the Constitution.

Perhaps you think your E-mail is legitimate enough that encryption is unwarranted.  If you really are a law-abiding citizen with nothing to hide, then why don't you always send your paper mail on postcards? Why not submit to drug testing on demand?  Why require a warrant for police searches of your house?  Are you trying to hide something? You must be a subversive or a drug dealer if you hide your mail inside envelopes.  Or maybe a paranoid nut.  Do law-abiding citizens have any need to encrypt their E-mail?

What if everyone believed that law-abiding citizens should use postcards for their mail?  If some brave soul tried to assert his privacy by using an envelope for his mail, it would draw suspicion.

Perhaps the authorities would open his mail to see what he's hiding. Fortunately, we don't live in that kind of world, because everyone protects most of their mail with envelopes.  So no one draws suspicion by asserting their privacy with an envelope.  There's safety in numbers.  Analogously, it would be nice if everyone routinely used encryption for all their E-mail, innocent or not, so that no one drew suspicion by asserting their E-mail privacy with encryption.  Think of it as a form of solidarity.

Today, if the Government wants to violate the privacy of ordinary citizens, it has to expend a certain amount of expense and labor to intercept and steam open and read paper mail, and listen to and possibly transcribe spoken telephone conversation.  This kind of labor-intensive monitoring is not practical on a large scale.  This is only done in important cases when it seems worthwhile.

More and more of our private communications are being routed through electronic channels.  Electronic mail is gradually replacing conventional paper mail.  E-mail messages are just too easy to

intercept and scan for interesting keywords.  This can be done easily, routinely, automatically, and undetectable on a grand scale.  International cablegrams are already scanned this way on a large

scale by the NSA.

We are moving toward a future when the nation will be crisscrossed with high capacity fiber optic data networks linking together all our increasingly ubiquitous personal computers.  E-mail will be the norm for everyone, not the novelty it is today.  The Government will protect our E-mail with Government-designed encryption protocols. Probably most people will acquiesce to that.  But perhaps some people will prefer their own protective measures.

Senate Bill 266, a 1991 omnibus anti-crime bill, had an unsettling measure buried in it.  If this non-binding resolution had become real law, it would have forced manufacturers of secure communications equipment to insert special "trap doors" in their products, so that the Government can read anyone's encrypted messages.  It reads:  "It is the sense of Congress that providers of electronic communications services and manufacturers of electronic communications service equipment shall insure that communications systems permit the Government to obtain the plain text contents of voice, data, and other communications when appropriately authorized by law."  This measure was defeated after rigorous protest from civil libertarians and industry groups.

In 1992, the FBI Digital Telephony wiretap proposal was introduced to Congress.  It would require all manufacturers of communications equipment to build in special remote wiretap ports that would enable the FBI to remotely wiretap all forms of electronic communication from FBI offices.  Although it never attracted any sponsors in Congress in 1992 because of citizen opposition, it was reintroduced in 1994.

Most alarming of all is the White House's bold new encryption policy initiative, under development at NSA since the start of the Bush administration, and unveiled April 16th, 1993.  The centerpiece of this initiative is a Government-built encryption device, called the "Clipper" chip, containing a new classified NSA encryption algorithm.  The Government is encouraging private industry to design it into all their secure communication products, like secure phones, secure FAX, etc.  AT&T is now putting the Clipper into their secure  voice products.  The catch:  At the time of manufacture, each Clipper chip will be loaded with its own unique key, and the Government gets

to keep a copy, placed in escrow.  Not to worry, though—the Government promises that they will use these keys to read your traffic only when duly authorized by law.  Of course, to make Clipper

completely effective, the next logical step would be to outlaw other forms of cryptography.

If privacy is outlawed, only outlaws will have privacy.  Intelligence agencies have access to good cryptographic technology.  So do the big arms and drug traffickers.  So do defense contractors, oil companies, and other corporate giants.  But ordinary people and grassroots political organizations mostly have not had access to affordable "military grade" public-key cryptographic technology.  Until now.

PGP empowers people to take their privacy into their own hands.   There's a growing social need for it.  That's why I wrote it.


How PGP Works
How it Works

============

It would help if you were already familiar with the concept of cryptography in general and public key cryptography in particular.  Nonetheless, here are a few introductory remarks about public key cryptography.

First, some elementary terminology.  Suppose I want to send you a message, but I don't want anyone but you to be able to read it.  I can "encrypt", or "encipher" the message, which means I scramble it up in a hopelessly complicated way, rendering it unreadable to anyone except you, the intended recipient of the message.  I supply a cryptographic "key" to encrypt the message, and you have to use the same key to decipher or "decrypt" it.  At least that's how it works in conventional "single-key" cryptosystems.

In conventional cryptosystems, such as the US Federal Data Encryption Standard (DES), a single key is used for both encryption and decryption.  This means that a key must be initially transmitted via secure channels so that both parties can know it before encrypted messages can be sent over insecure channels.  This may be inconvenient.  If you have a secure channel for exchanging keys, then why do you need cryptography in the first place?

In public key cryptosystems, everyone has two related complementary keys, a publicly revealed key and a secret key (also frequently called a private key).  Each key unlocks the code that the other key makes.  Knowing the public key does not help you deduce the corresponding

secret key.  The public key can be published and widely disseminated across a communications network.  This protocol provides privacy without the need for the same kind of secure channels that a

conventional cryptosystem requires.

Anyone can use a recipient's public key to encrypt a message to that person, and that recipient uses her own corresponding secret key to decrypt that message.  No one but the recipient can decrypt it, because no one else has access to that secret key.  Not even the person who encrypted the message can decrypt it.

Message authentication is also provided.  The sender's own secret key can be used to encrypt a message, thereby "signing" it.  This creates a digital signature of a message, which the recipient (or anyone else) can check by using the sender's public key to decrypt it.  This proves that the sender was the true originator of the message, and that the message has not been subsequently altered by anyone else, because the sender alone possesses the secret key that made that

signature.  Forgery of a signed message is infeasible, and the sender cannot later disavow his signature.

These two processes can be combined to provide both privacy and authentication by first signing a message with your own secret key, then encrypting the signed message with the recipient's public key.  The recipient reverses these steps by first decrypting the message with her own secret key, then checking the enclosed signature with your public key.  These steps are done automatically by the recipient's software.

Because the public key encryption algorithm is much slower than conventional single-key encryption, encryption is better accomplished by using a high-quality fast conventional single-key encryption algorithm to encipher the message.  This original unenciphered message is called "plaintext".  In a process invisible to the user, a temporary random key, created just for this one "session", is used to conventionally encipher the plaintext file.  Then the recipient's public key is used to encipher this temporary random conventional key.  This public-key-enciphered conventional "session" key is sent along with the enciphered text (called "ciphertext") to the recipient.  The recipient uses her own secret key to recover this temporary session key, and then uses that key to run the fast

conventional single-key algorithm to decipher the large ciphertext  message.

Public keys are kept in individual "key certificates" that include the key owner's user ID (which is that person's name), a timestamp of when the key pair was generated, and the actual key material.  Public key certificates contain the public key material, while secret key certificates contain the secret key material.  Each secret key is also encrypted with its own password, in case it gets stolen.  A key

file, or "key ring" contains one or more of these key certificates.  Public key rings contain public key certificates, and secret key rings contain secret key certificates.

The keys are also internally referenced by a "key ID", which is an "abbreviation" of the public key (the least significant 64 bits of  the large public key).  When this key ID is displayed, only the lower

32 bits are shown for further brevity.  While many keys may share the same user ID, for all practical purposes no two keys share the same key ID.

PGP uses "message digests" to form signatures.  A message digest is a 128-bit cryptographically strong one-way hash function of the message.  It is somewhat analogous to a "checksum" or CRC error checking code, in that it compactly "represents" the message and is

used to detect changes in the message.  Unlike a CRC, however, it is computationally infeasible for an attacker to devise a substitute message that would produce an identical message digest.  The message digest gets encrypted by the secret key to form a signature.

Documents are signed by prefixing them with signature certificates, which contain the key ID of the key that was used to sign it, a secret-key-signed message digest of the document, and a time stamp of when the signature was made.  The key ID is used by the receiver to look up the sender's public key to check the signature.  The receiver's software automatically looks up the sender's public key and user ID in the receiver's public key ring.

Encrypted files are prefixed by the key ID of the public key used to encrypt them.  The receiver uses this key ID message prefix to look up the secret key needed to decrypt the message.  The receiver's  software automatically looks up the necessary secret decryption key in the receiver's secret key ring.

These two types of key rings are the principal method of storing and managing public and secret keys.  Rather than keep individual keys in separate key files, they are collected in key rings to facilitate the automatic lookup of keys either by key ID or by user ID.  Each user keeps his own pair of key rings.  An individual public key is temporarily kept in a separate file long enough to send to your

friend who will then add it to her key ring.


Installing PGP From Dos
Installing PGP

==============

The MSDOS PGP release package comes in a compressed archive file with a file named in this form: PGPxx.ZIP (each release version has a different number for the "xx" in the filename).  For example, the release package for version 2.6 is called PGP26.ZIP.  The archive can be decompressed with the MSDOS shareware decompression utility PKUNZIP, or the Unix utility "unzip".  When the PGP release package is decompressed, several files emerge from it.  One such file, called

README.DOC, should always be read before installing PGP.  This file contains late-breaking news on what's new in this release of PGP, as well as information on what's in all the other files included in the release.

If you already have an earlier version of PGP, you should rename it or delete it, to avoid name conflicts with the new PGP.

For full details on how to install PGP, see the separate PGP Installation Guide, in the file SETUP.DOC included with this release package.  It fully describes how to set up the PGP directory and your AUTOEXEC.BAT file and how to use PKUNZIP to install it.  We will just briefly summarize the installation instructions here, in case you are too impatient to read the more detailed installation manual right now.

To install PGP on your MSDOS system, you have to copy the compressed archive PGPxx.ZIP file into a suitable directory on your hard disk (like C:\PGP), and decompress it with PKUNZIP.  For best results, you should also modify your AUTOEXEC.BAT file, as described elsewhere in

this manual, but you can do that later, after you've played with PGP a bit and read more of this manual.  If you haven't run PGP before, the first step after installation (and reading this manual) is to

make a pair of keys for yourself by running the PGP key generation command "pgp -kg".  Read the "RSA Key Generation" section of the manual first.

Installing on Unix and VAX/VMS is generally similar to installing on MSDOS, but you may have to compile the source code first.  A Unix makefile is provided with the source release for this purpose.


PGP Usage Summary

To See a Usage Summary

----------------------

To see a quick command usage summary for PGP, just type:

    pgp -h


Encrypting A Message In DOS

Encrypting a Message

--------------------

To encrypt a plaintext file with the recipient's public key, type:

    pgp -e textfile her_userid

This command produces a ciphertext file called textfile.pgp.  A specific example is:

    pgp -e letter.txt Alice

or:

    pgp -e letter.txt "Alice S"

The first example searches your public key ring file "pubring.pgp" for any public key certificates that contain the string "Alice" anywhere in the user ID field.  The second example would find any user IDs that contain "Alice S".  You can't use spaces in the string on the command line unless you enclose the whole string in quotes. The search is not case-sensitive.  If it finds a matching public key, it uses it to encrypt the plaintext file "letter.txt", producing a ciphertext file called "letter.pgp".

PGP attempts to compress the plaintext before encrypting it, thereby greatly enhancing resistance to cryptanalysis.  Thus the ciphertext file will likely be smaller than the plaintext file.

If you want to send this encrypted message through E-mail channels, convert it into printable ASCII "radix-64" format by adding the -a option, as described later.


Encrypting A Message To Mult. Recipients In DOS

Encrypting a Message to Multiple Recipients

-------------------------------------------

If you want to send the same message to more than one person, you may specify encryption for several recipients, any of whom may decrypt the same ciphertext file.  To specify multiple recipients, just add more user IDs to the command line, like so:

    pgp -e letter.txt Alice Bob Carol

This would create a ciphertext file called letter.pgp that could be decrypted by Alice or Bob or Carol.  Any number of recipients may be specified.


Signing A Message In DOS

Signing a Message

-----------------

To sign a plaintext file with your secret key, type:

    pgp -s textfile [-u your_userid]

Note that [brackets] denote an optional field, so don't actually type real brackets.

This command produces a signed file called textfile.pgp.  A specific example is:

    pgp -s letter.txt -u Bob

This searches your secret key ring file "secring.pgp" for any secret key certificates that contain the string "Bob" anywhere in the user ID field.  Your name is Bob, isn't it?  The search is not

case-sensitive.  If it finds a matching secret key, it uses it to sign the plaintext file "letter.txt", producing a signature file called "letter.pgp".

If you leave off the user ID field, the first key on your secret key ring is used as the default secret key for your signature.

PGP attempts to compress the message after signing it.  Thus the signed file will likely be smaller than the original file, which is useful for archival applications.  However, this renders the file

unreadable to the casual human observer, even if the original message was ordinary ASCII text.  It would be nice if you could make a signed file that was still directly readable to a human.  This would be particularly useful if you want to send a signed message as E-mail.

For signing E-mail messages, where you most likely do want the result to be human-readable, it is probably most convenient to use the CLEARSIG feature, explained later.  This allows the signature to be applied in printable form at the end of the text, and also disables

compression of the text.  This means the text is still human-readable by the recipient even if the recipient doesn't use PGP to check the signature.  This is explained in detail in the section entitled

"CLEARSIG - Enable Signed Messages to be Encapsulated as Clear Text", in the Special Topics volume.  If you can't wait to read that section of the manual, you can see how an E-mail message signed this way would look, with this example:

     pgp -sta message.txt

This would create a signed message in file "message.asc", comprised of the original text, still human-readable, appended with a printable ASCII signature certificate, ready to send through an E-mail system.  This example assumes that you are using the normal settings for enabling the CLEARSIG flag in the config file.


Signing & Then Encrypting

Signing and then Encrypting

---------------------------

To sign a plaintext file with your secret key, and then encrypt it with the recipient's public key:

    pgp -es textfile her_userid [-u your_userid]

Note that [brackets] denote an optional field, so don't actually type real brackets.

This example produces a nested ciphertext file called textfile.pgp. Your secret key to create the signature is automatically looked up in your secret key ring via your_userid.  Her public encryption key is automatically looked up in your public key ring via her_userid.  If you leave off her user ID field from the command line, you will be prompted for it.

If you leave off your own user ID field, the first key on your secret key ring is be used as the default secret key for your signature.

Note that PGP attempts to compress the plaintext before encrypting it.

If you want to send this encrypted message through E-mail channels, convert it into printable ASCII "radix-64" format by adding the -a option, as described later.

Multiple recipients may be specified by adding more user IDs to the command line.


Conventional Encryption In DOS

Using Just Conventional Encryption

----------------------------------

Sometimes you just need to encrypt a file the old-fashioned way, with conventional single-key cryptography.  This approach is useful for protecting archive files that will be stored but will not be sent to anyone else.  Since the same person that encrypted the file will also decrypt the file, public key cryptography is not really necessary.

To encrypt a plaintext file with just conventional cryptography, type:

    pgp -c textfile

This example encrypts the plaintext file called textfile, producing a ciphertext file called textfile.pgp, without using public key cryptography, key rings, user IDs, or any of that stuff.  It prompts

you for a pass phrase to use as a conventional key to encipher the file.  This pass phrase need not be (and, indeed, SHOULD not be) the same pass phrase that you use to protect your own secret key.  Note that PGP attempts to compress the plaintext before encrypting it.

PGP will not encrypt the same plaintext the same way twice, even if you used the same pass phrase every time.


Decrypting & Checking Signatures In DOS

Decrypting and Checking Signatures

----------------------------------

To decrypt an encrypted file, or to check the signature integrity of a signed file:

    pgp ciphertextfile [-o plaintextfile]

Note that [brackets] denote an optional field, so don't actually type real brackets.

The ciphertext file name is assumed to have a default extension of ".pgp".  The optional plaintext output file name specifies where to put processed plaintext output.  If no name is specified, the ciphertext filename is used, with no extension.  If a signature is nested inside of an encrypted file, it is automatically decrypted and the signature integrity is checked.  The full user ID of the signer

is displayed.

Note that the "unwrapping" of the ciphertext file is completely automatic, regardless of whether the ciphertext file is just signed, just encrypted, or both.  PGP uses the key ID prefix in the

ciphertext file to automatically find the appropriate secret decryption key on your secret key ring.  If there is a nested signature, PGP then uses the key ID prefix in the nested signature to automatically find the appropriate public key on your public key ring to check the signature.  If all the right keys are already present on your key rings, no user intervention is required, except that you will be prompted for your password for your secret key if necessary. If the ciphertext file was conventionally encrypted without public key cryptography, PGP recognizes this and prompts you for the pass phrase to conventionally decrypt it.


RSA Key Generation In DOS

RSA Key Generation

------------------

To generate your own unique public/secret key pair of a specified size, type:

    pgp -kg

PGP shows you a menu of recommended key sizes (low commercial grade, high commercial grade, or "military" grade) and prompts you for what size key you want, up to more than a thousand bits.  The bigger the key, the more security you get, but you pay a price in speed.

It also asks for a user ID, which means your name.  It's a good idea to use your full name as your user ID, because then there is less risk of other people using the wrong public key to encrypt messages to you.  Spaces and punctuation are allowed in the user ID.  It would help if you put your E-mail address in <angle brackets> after your name, like so:

    Robert M. Smith <rms@xyzcorp.com>

If you don't have an E-mail address, use your phone number or some other unique information that would help ensure that your user ID is unique.

PGP also asks for a "pass phrase" to protect your secret key in case it falls into the wrong hands.  Nobody can use your secret key file without this pass phrase.  The pass phrase is like a password, except that it can be a whole phrase or sentence with many words, spaces,

punctuation, or anything else you want in it.  Don't lose this pass phrase-- there's no way to recover it if you do lose it.  This pass phrase will be needed later every time you use your secret key.  The

pass phrase is case-sensitive, and should not be too short or easy to guess.  It is never displayed on the screen.  Don't leave it written down anywhere where someone else can see it, and don't store it on

your computer.  If you don't want a pass phrase (You fool!), just press return (or enter) at the pass phrase prompt.

The public/secret key pair is derived from large truly random numbers derived mainly from measuring the intervals between your keystrokes with a fast timer.  The software will ask you to enter some random text to help it accumulate some random bits for the keys.  When asked, you should provide some keystrokes that are reasonably random in their timing, and it wouldn't hurt to make the actual characters that you type irregular in content as well.  Some of the randomness is derived from the unpredictability of the content of what you type.  So don't just type repeated sequences of characters.

Note that RSA key generation is a lengthy process.  It may take a few seconds for a small key on a fast processor, or quite a few minutes for a large key on an old IBM PC/XT.  PGP will visually indicate its progress during key generation.

The generated key pair will be placed on your public and secret key rings.  You can later use the -kx command option to extract (copy) your new public key from your public key ring and place it in a separate public key file suitable for distribution to your friends.  The public key file can be sent to your friends for inclusion in their public key rings.  Naturally, you keep your secret key file to yourself, and you should include it on your secret key ring.  Each secret key on a key ring is individually protected with its own pass phrase.

Never give your secret key to anyone else.  For the same reason, don't  make key pairs for your friends.  Everyone should make their own key pair.  Always keep physical control of your secret key, and don't risk exposing it by storing it on a remote timesharing computer.  Keep it on your own personal computer.

If PGP complains about not being able to find the PGP User's Guide on your computer, and refuses to generate a key pair without it, don't panic.  Just read the explanation of the NOMANUAL parameter in the section "Setting Configuration Parameters" in the Special Topics volume of the PGP User's Guide.


Adding A Key To Your Key Ring In DOS

Adding a Key to Your Key Ring

-----------------------------

Sometimes you will want to add to your keyring a key provided to you by someone else, in the form of a keyfile.

To add a public or secret key file's contents to your public or secret key ring (note that [brackets] denote an optional field):

    pgp -ka keyfile [keyring]

The keyfile extension defaults to ".pgp".  The optional keyring file name defaults to "pubring.pgp" or "secring.pgp", depending on whether the keyfile contains a public or a secret key.  You may specify a different key ring file name, with the extension defaulting to ".pgp".

If the key is already on your key ring, PGP will not add it again.  All of the keys in the keyfile are added to the keyring, except for duplicates.

Later in the manual, we will explain the concept of certifying keys with signatures.  If the key being added has attached signatures certifying it, the signatures are added with the key.  If the key is

already on your key ring, PGP just merges in any new certifying signatures for that key that you don't already have on your key ring.

PGP was originally designed for handling small personal keyrings.  If you want to handle really big keyrings, see the section on "Handling Large Public Keyrings" in the Special Topics volume.


Removing Keys From Your Key Ring In DOS

Removing a Key or User ID from Your Key Ring

--------------------------------------------

To remove a key or a user ID from your public key ring:

    pgp -kr userid [keyring]

This searches for the specified user ID in your key ring, and removes it if it finds a match.  Remember that any fragment of the user ID will suffice for a match.  The optional keyring file name is assumed to be literally "pubring.pgp".  It can be omitted, or you can specify "secring.pgp" if you want to remove a secret key.  You may specify a different key ring file name.  The default key ring extension is ".pgp".

If more than one user ID exists for this key, you will be asked if you want to remove only the user ID you specified, while leaving the key and its other user IDs intact.


Extracting Keys From Key Ring In DOS

Extracting (copying) a Key from Your Key Ring

---------------------------------------------

To extract (copy) a key from your public or secret key ring:

    pgp -kx userid keyfile [keyring]

This non-destructively copies the key specified by the user ID from your public or secret key ring to the specified key file.  This is particularly useful if you want to give a copy of your public key to

someone else.

If the key has any certifying signatures attached to it on your key ring, they are copied off along with the key.

If you want the extracted key represented in printable ASCII characters suitable for email purposes, use the -kxa options.


Viewing Keys In DOS

Viewing the Contents of Your Key Ring

-------------------------------------

To view the contents of your public key ring:

    pgp -kv[v] [userid] [keyring]

This lists any keys in the key ring that match the specified user ID substring.  If you omit the user ID, all of the keys in the key ring are listed.  The optional keyring file name is assumed to be

"pubring.pgp".  It can be omitted, or you can specify "secring.pgp" if you want to list secret keys.  If you want to specify a different key ring file name, you can.  The default key ring extension is ".pgp".

Later in the manual, we will explain the concept of certifying keys with signatures.  To see all the certifying signatures attached to each key, use the -kvv option:

    pgp -kvv [userid] [keyring]

If you want to specify a particular key ring file name, but want to see all the keys in it, try this alternative approach:

    pgp keyfile

With no command options specified, PGP lists all the keys in keyfile.pgp, and also attempts to add them to your key ring if they are not already on your key ring.


Protecting From Key Tampering

How to Protect Public Keys from Tampering

-----------------------------------------

In a public key cryptosystem, you don't have to protect public keys from exposure.  In fact, it's better if they are widely disseminated. But it is important to protect public keys from tampering, to make sure that a public key really belongs to whom it appears to belong to. This may be the most important vulnerability of a public-key cryptosystem.  Let's first look at a potential disaster, then at how

to safely avoid it with PGP.

Suppose you wanted to send a private message to Alice.  You download Alice's public key certificate from an electronic bulletin board system (BBS).  You encrypt your letter to Alice with this public key and send it to her through the BBS's E-mail facility.

Unfortunately, unbeknownst to you or Alice, another user named Charlie has infiltrated the BBS and generated a public key of his own with Alice's user ID attached to it.  He covertly substitutes his bogus key in place of Alice's real public key.  You unwittingly use this bogus key belonging to Charlie instead of Alice's public key.  All looks normal because this bogus key has Alice's user ID.  Now Charlie can decipher the message intended for Alice because he has the matching secret key.  He may even re-encrypt the deciphered message with Alice's real public key and send it on to her so that no one suspects any wrongdoing.  Furthermore, he can even make apparently good signatures from Alice with this secret key because everyone will use the bogus public key to check Alice's signatures.

The only way to prevent this disaster is to prevent anyone from tampering with public keys.  If you got Alice's public key directly from Alice, this is no problem.  But that may be difficult if Alice

is a thousand miles away, or is currently unreachable.

Perhaps you could get Alice's public key from a mutual trusted friend David who knows he has a good copy of Alice's public key.  David could sign Alice's public key, vouching for the integrity of Alice's public key.  David would create this signature with his own secret key.

This would create a signed public key certificate, and would show that Alice's key had not been tampered with.  This requires you have a known good copy of David's public key to check his signature.  Perhaps David could provide Alice with a signed copy of your public key also. David is thus serving as an "introducer" between you and Alice.

This signed public key certificate for Alice could be uploaded by David or Alice to the BBS, and you could download it later.  You could then check the signature via David's public key and thus be assured that this is really Alice's public key.  No impostor can fool you into accepting his own bogus key as Alice's because no one else can forge signatures made by David.

A widely trusted person could even specialize in providing this service of "introducing" users to each other by providing signatures for their public key certificates.  This trusted person could be

regarded as a "key server", or as a "Certifying Authority".  Any public key certificates bearing the key server's signature could be trusted as truly belonging to whom they appear to belong to.  All users who wanted to participate would need a known good copy of just the key server's public key, so that the key server's signatures could be verified.

A trusted centralized key server or Certifying Authority is especially appropriate for large impersonal centrally-controlled corporate or government institutions.  Some institutional

environments use hierarchies of Certifying Authorities.

For more decentralized grassroots "guerrilla style" environments, allowing all users to act as a trusted introducers for their friends would probably work better than a centralized key server.  PGP tends to emphasize this organic decentralized non-institutional approach.  It better reflects the natural way humans interact on a personal social level, and allows people to better choose who they can trust

for key management.

This whole business of protecting public keys from tampering is the single most difficult problem in practical public key applications.  It is the Achilles' heel of public key cryptography, and a lot of software complexity is tied up in solving this one problem.

You should use a public key only after you are sure that it is a good public key that has not been tampered with, and actually belongs to the person it claims to.  You can be sure of this if you got this public key certificate directly from its owner, or if it bears the signature of someone else that you trust, from whom you already have a good public key.  Also, the user ID should have the full name of

the key's owner, not just her first name.

No matter how tempted you are-- and you will be tempted-- never, NEVER give in to expediency and trust a public key you downloaded from a bulletin board, unless it is signed by someone you trust.  That uncertified public key could have been tampered with by anyone,

maybe even by the system administrator of the bulletin board.

If you are asked to sign someone else's public key certificate, make certain that it really belongs to that person named in the user ID of that public key certificate.  This is because your signature on her public key certificate is a promise by you that this public key really belongs to her.  Other people who trust you will accept her public key because it bears your signature.  It may be ill-advised to rely on hearsay-- don't sign her public key unless you have independent firsthand knowledge that it really belongs to her.  Preferably, you should sign it only if you got it directly from her.

In order to sign a public key, you must be far more certain of that key's ownership than if you merely want to use that key to encrypt a message.  To be convinced of a key's validity enough to use it, certifying signatures from trusted introducers should suffice.  But to sign a key yourself, you should require your own independent firsthand knowledge of who owns that key.  Perhaps you could call the

key's owner on the phone and read the key file to her to get her to confirm that the key you have really is her key-- and make sure you really are talking to the right person.  See the section called "Verifying a Public Key Over the Phone" in the Special Topics volume for further details.

Bear in mind that your signature on a public key certificate does not vouch for the integrity of that person, but only vouches for the integrity (the ownership) of that person's public key.  You aren't

risking your credibility by signing the public key of a sociopath, if you were completely confident that the key really belonged to him. Other people would accept that key as belonging to him because you

signed it (assuming they trust you), but they wouldn't trust that key's owner.  Trusting a key is not the same as trusting the key's owner.

Trust is not necessarily transferable; I have a friend who I trust not to lie.  He's a gullible person who trusts the President not to lie.  That doesn't mean I trust the President not to lie.  This is

just common sense.  If I trust Alice's signature on a key, and Alice trusts Charlie's signature on a key, that does not imply that I have to trust Charlie's signature on a key.

It would be a good idea to keep your own public key on hand with a collection of certifying signatures attached from a variety of "introducers", in the hopes that most people will trust at least one

of the introducers who vouch for your own public key's validity. You could post your key with its attached collection of certifying signatures on various electronic bulletin boards.  If you sign

someone else's public key, return it to them with your signature so that they can add it to their own collection of credentials for their own public key.

PGP keeps track of which keys on your public key ring are properly certified with signatures from introducers that you trust.  All you have to do is tell PGP which people you trust as introducers, and certify their keys yourself with your own ultimately trusted key. PGP can take it from there, automatically validating any other keys that have been signed by your designated introducers.  And of course you may directly sign more keys yourself.  More on this later.

Make sure no one else can tamper with your own public key ring. Checking a new signed public key certificate must ultimately depend on the integrity of the trusted public keys that are already on your own public key ring.  Maintain physical control of your public key ring, preferably on your own personal computer rather than on a remote timesharing system, just as you would do for your secret key.  This is to protect it from tampering, not from disclosure.  Keep a trusted backup copy of your public key ring and your secret key ring on write-protected media.

Since your own trusted public key is used as a final authority to directly or indirectly certify all the other keys on your key ring, it is the most important key to protect from tampering.  To detect

any tampering of your own ultimately-trusted public key, PGP can be set up to automatically compare your public key against a backup copy on write-protected media.  For details, see the description of the "-kc" key ring check command in the Special Topics volume.

PGP generally assumes you will maintain physical security over your system and your key rings, as well as your copy of PGP itself.  If an intruder can tamper with your disk, then in theory he can tamper with PGP itself, rendering moot the safeguards PGP may have to detect tampering with keys.

One somewhat complicated way to protect your own whole public key ring from tampering is to sign the whole ring with your own secret key.  You could do this by making a detached signature certificate of the public key ring, by signing the ring with the "-sb" options (see the section called "Separating Signatures from Messages" in the PGP User's Guide, Special Topics volume).  Unfortunately, you would still have to keep a separate trusted copy of your own public key around to

check the signature you made.  You couldn't rely on your own public key stored on your public key ring to check the signature you made for the whole ring, because that is part of what you're trying to

check.


Valid Key Tracking

How Does PGP Keep Track of Which Keys are Valid?

------------------------------------------------

Before you read this section, be sure to read the above section on "How to Protect Public Keys from Tampering".

PGP keeps track of which keys on your public key ring are properly certified with signatures from introducers that you trust.  All you have to do is tell PGP which people you trust as introducers, and certify their keys yourself with your own ultimately trusted key. PGP can take it from there, automatically validating any other keys that have been signed by your designated introducers.  And of course you may directly sign more keys yourself.

There are two entirely separate criteria PGP uses to judge a public key's usefulness-- don't get them confused:

  1)  Does the key actually belong to whom it appears to belong?

       In other words, has it been certified with a trusted signature?

  2)  Does it belong to someone you can trust to certify other keys?

PGP can calculate the answer to the first question.  To answer the second question, PGP must be explicitly told by you, the user.  When you supply the answer to question 2, PGP can then calculate the answer to question 1 for other keys signed by the introducer you designated as trusted.

Keys that have been certified by a trusted introducer are deemed valid by PGP.  The keys belonging to trusted introducers must themselves be certified either by you or by other trusted

introducers.

PGP also allows for the possibility of you having several shades of trust for people to act as introducers.  Your trust for a key's owner to act as an introducer does not just reflect your estimation of

their personal integrity-- it should also reflect how competent you think they are at understanding key management and using good judgment in signing keys.  You can designate a person to PGP as

unknown, untrusted, marginally trusted, or completely trusted to certify other public keys.  This trust information is stored on your key ring with their key, but when you tell PGP to copy a key off your

key ring, PGP will not copy the trust information along with the key, because your private opinions on trust are regarded as confidential.

When PGP is calculating the validity of a public key, it examines the trust level of all the attached certifying signatures.  It computes a weighted score of validity-- two marginally trusted signatures are deemed as credible as one fully trusted signature.  PGP's skepticism

is adjustable-- for example, you may tune PGP to require two fully trusted signatures or three marginally trusted signatures to judge a key as valid.

Your own key is "axiomatically" valid to PGP, needing no introducer's signature to prove its validity.  PGP knows which public keys are yours, by looking for the corresponding secret keys on the secret key ring.  PGP also assumes you ultimately trust yourself to certify other keys.

As time goes on, you will accumulate keys from other people that you may want to designate as trusted introducers.  Everyone else will each choose their own trusted introducers.  And everyone will gradually accumulate and distribute with their key a collection of certifying signatures from other people, with the expectation that anyone receiving it will trust at least one or two of the signatures.

This will cause the emergence of a decentralized fault-tolerant web of confidence for all public keys.

This unique grass-roots approach contrasts sharply with Government standard public key management schemes, such as Internet Privacy Enhanced Mail (PEM), which are based on centralized control and mandatory centralized trust.  The standard schemes rely on a hierarchy of Certifying Authorities who dictate who you must trust.  PGP's decentralized probabilistic method for determining public key legitimacy is the centerpiece of its key management architecture.  PGP lets you alone choose who you trust, putting you at the top of  your own private certification pyramid.  PGP is for people who prefer to pack their own parachutes.


Protecting From Key Disclosure

How to Protect Secret Keys from Disclosure

------------------------------------------

Protect your own secret key and your pass phrase carefully.  Really, really carefully.  If your secret key is ever compromised, you'd better get the word out quickly to all interested parties (good luck) before someone else uses it to make signatures in your name.  For example, they could use it to sign bogus public key certificates, which could create problems for many people, especially if your

signature is widely trusted.  And of course, a compromise of your own secret key could expose all messages sent to you.

To protect your secret key, you can start by always keeping physical control of your secret key.  Keeping it on your personal computer at home is OK, or keep it in your notebook computer that you can carry with you.  If you must use an office computer that you don't always have physical control of, then keep your public and secret key rings on a write-protected removable floppy disk, and don't leave it behind when you leave the office.  It wouldn't be a good idea to allow your secret key to reside on a remote timesharing computer, such as a remote dial-in Unix system.  Someone could eavesdrop on your modem line and capture your pass phrase, and then obtain your actual secret key from the remote system.  You should only use your secret key on a machine that you have physical control over.

Don't store your pass phrase anywhere on the computer that has your secret key file.  Storing both the secret key and the pass phrase on the same computer is as dangerous as keeping your PIN in the same wallet as your Automatic Teller Machine bank card.  You don't want somebody to get their hands on your disk containing both the pass phrase and the secret key file.  It would be most secure if you just memorize your pass phrase and don't store it anywhere but your brain.  If you feel you must write down your pass phrase, keep it well protected, perhaps even more well protected than the secret key file.

And keep backup copies of your secret key ring-- remember, you have the only copy of your secret key, and losing it will render useless all the copies of your public key that you have spread throughout the world.

The decentralized non-institutional approach PGP uses to manage public keys has its benefits, but unfortunately this also means we can't rely on a single centralized list of which keys have been compromised.  This makes it a bit harder to contain the damage of a secret key compromise.  You just have to spread the word and hope everyone hears about it.

If the worst case happens-- your secret key and pass phrase are both compromised (hopefully you will find this out somehow)-- you will have to issue a "key compromise" certificate.  This kind of certificate is used to warn other people to stop using your public key.  You can use PGP to create such a certificate by using the "-kd" command.  Then you must somehow send this compromise certificate to everyone else on the planet, or at least to all your friends and their friends, et cetera.  Their own PGP software will install this key compromise certificate on their public key rings and will automatically prevent them from accidentally using your public key ever again.  You can then generate a new secret/public key pair and publish the new public key.  You could send out one package containing both your new public key and the key compromise certificate for your old key.


Revoking Keys In DOS

Revoking a Public Key

---------------------

Suppose your secret key and your pass phrase are somehow both compromised.  You have to get the word out to the rest of the world, so that they will all stop using your public key.  To do this, you will have to issue a "key compromise", or "key revocation" certificate to revoke your public key.

To generate a certificate to revoke your own key, use the -kd command:

     pgp -kd your_userid

This certificate bears your signature, made with the same key you are revoking.  You should widely disseminate this key revocation certificate as soon as possible.  Other people who receive it can add it to their public key rings, and their PGP software then automatically prevents them from accidentally using your old public key ever again.  You can then generate a new secret/public key pair

and publish the new public key.

You may choose to revoke your key for some other reason than the compromise of a secret key.  If so, you may still use the same mechanism to revoke it.


What If You Lose Your Secret Key

What If You Lose Your Secret Key?

---------------------------------

Normally, if you want to revoke your own secret key, you can use the "-kd" command to issue a revocation certificate, signed with your own secret key (see "Revoking a Public Key").

But what can you do if you lose your secret key, or if your secret key is destroyed?  You can't revoke it yourself, because you must use your own secret key to revoke it, and you don't have it anymore.  A future version of PGP will offer a more secure means of revoking keys in these circumstances, allowing trusted introducers to certify that a public key has been revoked.  But for now, you will have to get the word out through whatever informal means you can, asking users to "disable" your public key on their own individual public key rings.

Other users may disable your public key on their own public key rings by using the "-kd" command.  If a user ID is specified that does not correspond to a secret key on the secret key ring, the -kd command will look for that user ID on the public key ring, and mark that public key as disabled.  A disabled key may not be used to encrypt any messages, and may not be extracted from the key ring with the -kx command.  It can still be used to check signatures, but a warning is displayed.  And if the user tries to add the same key again to his key ring, it will not work because the disabled key is already on the key ring.  These combined features will help curtail the further spread of a disabled key.

If the specified public key is already disabled, the -kd command will ask if you want the key reenabled.


E-Mail & Radix-64

Sending Ciphertext Through E-mail Channels: Radix-64 Format

-----------------------------------------------------------

Many electronic mail systems only allow messages made of ASCII text, not the 8-bit raw binary data that ciphertext is made of.  To get around this problem, PGP supports ASCII radix-64 format for ciphertext messages, similar to the Internet Privacy-Enhanced Mail (PEM) format, as well as the Internet MIME format.  This special format represents binary data by using only printable ASCII

characters, so it is useful for transmitting binary encrypted data through 7-bit channels or for sending binary encrypted data as normal E-mail text.  This format acts as a form of "transport armor",

protecting it against corruption as it travels through intersystem gateways on Internet.  PGP also appends a CRC to detect transmission errors.

Radix-64 format converts the plaintext by expanding groups of 3 binary 8-bit bytes into 4 printable ASCII characters, so the file grows by about 33%.  But this expansion isn't so bad when you

consider that the file probably was compressed more than that by PGP before it was encrypted.

To produce a ciphertext file in ASCII radix-64 format, just add the "a" option when encrypting or signing a message, like so:

    pgp -esa message.txt her_userid

This example produces a ciphertext file called "message.asc" that contains data in a MIME-like ASCII radix-64 format.  This file can be easily uploaded into a text editor through 7-bit channels for

transmission as normal E-mail on Internet or any other E-mail network.

Decrypting the radix-64 transport-armored message is no different than a normal decrypt.  For example:

    pgp message

PGP automatically looks for the ASCII file "message.asc" before it looks for the binary file "message.pgp".  It recognizes that the file is in radix-64 format and converts it back to binary before

processing as it normally does, producing as a by-product a ".pgp" ciphertext file in binary form.  The final output file is in normal plaintext form, just as it was in the original file "message.txt".

Most Internet E-mail facilities prohibit sending messages that are more than 50000 or 65000 bytes long.  Longer messages must be broken into smaller chunks that can be mailed separately.  If your encrypted message is very large, and you requested radix-64 format, PGP automatically breaks it up into chunks that are each small enough to send via E-mail.  The chunks are put into files named with extensions ".as1", ".as2", ".as3", etc.  The recipient must concatenate these separate files back together in their proper order into one big file before decrypting it.  While decrypting, PGP ignores any extraneous text in mail headers that are not enclosed in the radix-64 message blocks.

If you want to send a public key to someone else in radix-64 format, just add the -a option while extracting the key from your keyring.

If you forgot to use the -a option when you made a ciphertext file or extracted a key, you may still directly convert the binary file into radix-64 format by simply using the -a option alone, without any

encryption specified.  PGP converts it to a ".asc" file.

If you sign a plaintext file without encrypting it, PGP will normally compress it after signing it, rendering it unreadable to the casual human observer.  This is a suitable way of storing signed files in

archival applications.  But if you want to send the signed message as E-mail, and the the original plaintext message is in text (not binary) form, there is a way to send it through an E-mail channel in

such a way that the plaintext does not get compressed, and the ASCII armor is applied only to the binary signature certificate, but not to the plaintext message.  This makes it possible for the recipient to read the signed message with human eyes, without the aid of PGP.  Of course, PGP is still needed to actually check the signature.  For further information on this feature, see the explanation of the

CLEARSIG parameter in the section "Setting Configuration Parameters" in the Special Topics volume.

Sometimes you may want to send a binary data file through an E-mail channel without encrypting or signing it with PGP.  Some people use the Unix uuencode utility for that purpose.  PGP can also be used for that purpose, by simply using the -a option alone, and it does a better job than the uuencode utility.  For further details, see the section on "Using PGP as a Better Uuencode" in the Special Topics volume.


Environmental Path

Environmental Variable for Path Name

------------------------------------

PGP uses several special files for its purposes, such as your standard key ring files "pubring.pgp" and "secring.pgp", the random number seed file "randseed.bin", the PGP configuration file "config.txt" (or "pgp.ini", or ".pgprc"), and the foreign language string translation file "language.txt".  These special files can be kept in any directory, by setting the environmental variable

"PGPPATH" to the desired pathname.  For example, on MSDOS, the shell command:

    SET PGPPATH=C:\PGP

makes PGP assume that your public key ring filename is "C:\PGP\pubring.pgp".  Assuming, of course, that this directory exists.  Use your favorite text editor to modify your MSDOS AUTOEXEC.BAT file to automatically set up this variable whenever you start up your system.  If PGPPATH remains undefined, these special files are assumed to be in the current directory.


Setting Parameters In The PGP Config. File

Setting Parameters in the PGP Configuration File

------------------------------------------------

PGP has a number of user-settable parameters that can be defined in a special PGP configuration text file called "config.txt", in the directory pointed to by the shell environmental variable PGPPATH.  Having a configuration file enables the user to define various flags and parameters for PGP without the burden of having to always define these parameters in the PGP command line.

In the interest of complying with local operating system file naming conventions, for Unix systems this configuration file may also be named ".pgprc", and on MSDOS systems it may also be named "pgp.ini".

With these configuration parameters, for example, you can control where PGP stores its temporary scratch files, or you can select what foreign language PGP will use to display its diagnostics messages and user prompts, or you can adjust PGP's level of skepticism in

determining a key's validity based on the number of certifying signatures it has.

For more details on setting these configuration parameters, see the appropriate section of the PGP User's Guide, Special Topics volume.


PGP Vulnerabilities
Vulnerabilities

---------------

No data security system is impenetrable.  PGP can be circumvented in a variety of ways.  Potential vulnerabilities you should be aware of include compromising your pass phrase or secret key, public key tampering, files that you deleted but are still somewhere on the disk, viruses and Trojan horses, breaches in your physical security, electromagnetic emissions, exposure on multi-user systems, traffic analysis, and perhaps even direct cryptanalysis.

For a detailed discussion of these issues, see the "Vulnerabilities" section in the PGP User's Guide, Special Topics volume.


Beware of Snake Oil

===================

When examining a cryptographic software package, the question always remains, why should you trust this product?  Even if you examined the source code yourself, not everyone has the cryptographic experience to judge the security.  Even if you are an experienced cryptographer,

subtle weaknesses in the algorithms could still elude you.

When I was in college in the early seventies, I devised what I believed was a brilliant encryption scheme.  A simple pseudorandom number stream was added to the plaintext stream to create ciphertext.  This would seemingly thwart any frequency analysis of the ciphertext, and would be uncrackable even to the most resourceful Government intelligence agencies.  I felt so smug about my

achievement.  So cock-sure.

Years later, I discovered this same scheme in several introductory cryptography texts and tutorial papers.  How nice.  Other cryptographers had thought of the same scheme.  Unfortunately, the

scheme was presented as a simple homework assignment on how to use elementary cryptanalytic techniques to trivially crack it.  So much for my brilliant scheme.

From this humbling experience I learned how easy it is to fall into a false sense of security when devising an encryption algorithm.  Most people don't realize how fiendishly difficult it is to devise an encryption algorithm that can withstand a prolonged and determined attack by a resourceful opponent.  Many mainstream software engineers have developed equally naive encryption schemes (often even the very same encryption scheme), and some of them have been incorporated into

commercial encryption software packages and sold for good money to thousands of unsuspecting users.

This is like selling automotive seat belts that look good and feel good, but snap open in even the slowest crash test.  Depending on them may be worse than not wearing seat belts at all.  No one

suspects they are bad until a real crash.  Depending on weak cryptographic software may cause you to unknowingly place sensitive information at risk.  You might not otherwise have done so if you had

no cryptographic software at all.  Perhaps you may never even discover your data has been compromised.

Sometimes commercial packages use the Federal Data Encryption Standard (DES), a fairly good conventional algorithm recommended by the Government for commercial use (but not for classified information, oddly enough-- hmmm).  There are several "modes of operation" the DES can use, some of them better than others.  The Government specifically recommends not using the weakest simplest mode for messages, the Electronic Codebook (ECB) mode.  But they do

recommend the stronger and more complex Cipher Feedback (CFB) or Cipher Block Chaining (CBC) modes.

Unfortunately, most of the commercial encryption packages I've looked at use ECB mode.  When I've talked to the authors of a number of these implementations, they say they've never heard of CBC or CFB modes, and didn't know anything about the weaknesses of ECB mode.  The very fact that they haven't even learned enough cryptography to know these elementary concepts is not reassuring.  And they sometimes manage their DES keys in inappropriate or insecure ways.  Also, these same software packages often include a second faster encryption algorithm that can be used instead of the slower DES.  The author of the package often thinks his proprietary faster algorithm is as secure as the DES, but after questioning him I usually discover that it's just a variation of my own brilliant scheme from college days.  Or maybe he won't even reveal how his proprietary encryption scheme

works, but assures me it's a brilliant scheme and I should trust it. I'm sure he believes that his algorithm is brilliant, but how can I know that without seeing it?

In all fairness I must point out that in most cases these terribly weak products do not come from companies that specialize in cryptographic technology.

Even the really good software packages, that use the DES in the correct modes of operation, still have problems.  Standard DES uses a 56-bit key, which is too small by today's standards, and may now be easily broken by exhaustive key searches on special high-speed machines.  The DES has reached the end of its useful life, and so has any software package that relies on it.

There is a company called AccessData (87 East 600 South, Orem, Utah 84058, phone 1-800-658-5199) that sells a package for $185 that cracks the built-in encryption schemes used by  WordPerfect, Lotus 1-2-3, MS Excel, Symphony, Quattro Pro, Paradox, and MS Word 2.0.  It

doesn't simply guess passwords-- it does real cryptanalysis.  Some people buy it when they forget their password for their own files.  Law enforcement agencies buy it too, so they can read files they

seize.  I talked to Eric Thompson, the author, and he said his program only takes a split second to crack them, but he put in some delay loops to slow it down so it doesn't look so easy to the customer.  He also told me that the password encryption feature of PKZIP files can often be easily broken, and that his law enforcement customers already have that service regularly provided to them from

another vendor.

In some ways, cryptography is like pharmaceuticals.  Its integrity may be absolutely crucial.  Bad penicillin looks the same as good penicillin.  You can tell if your spreadsheet software is wrong, but how do you tell if your cryptography package is weak?  The ciphertext produced by a weak encryption algorithm looks as good as ciphertext produced by a strong encryption algorithm.  There's a lot of snake oil out there.  A lot of quack cures.  Unlike the patent medicine hucksters of old, these software implementors usually don't even know their stuff is snake oil.  They may be good software engineers, but  they usually haven't even read any of the academic literature in cryptography.  But they think they can write good cryptographic software.  And why not?  After all, it seems intuitively easy to do so.  And their software seems to work okay.

Anyone who thinks they have devised an unbreakable encryption scheme either is an incredibly rare genius or is naive and inexperienced. Unfortunately, I sometimes have to deal with would-be cryptographers who want to make "improvements" to PGP by adding encryption algorithms of their own design.

I remember a conversation with Brian Snow, a highly placed senior cryptographer with the NSA.  He said he would never trust an encryption algorithm designed by someone who had not "earned their bones" by first spending a lot of time cracking codes.  That did make a lot of sense.  I observed that practically no one in the commercial world of cryptography qualified under this criterion.  "Yes", he said with a self assured smile, "And that makes our job at NSA so much easier."  A chilling thought.  I didn't qualify either.

The Government has peddled snake oil too.  After World War II, the US sold German Enigma ciphering machines to third world governments. But they didn't tell them that the Allies cracked the Enigma code during the war, a fact that remained classified for many years.  Even today many Unix systems worldwide use the Enigma cipher for file encryption, in part because the Government has created legal obstacles against using better algorithms.  They even tried to prevent the initial publication of the RSA algorithm in 1977.  And they have squashed essentially all commercial efforts to develop effective secure telephones for the general public.

The principal job of the US Government's National Security Agency is to gather intelligence, principally by covertly tapping into people's private communications (see James Bamford's book, "The Puzzle Palace").  The NSA has amassed considerable skill and resources for cracking codes.  When people can't get good cryptography to protect themselves, it makes NSA's job much easier.  NSA also has the responsibility of approving and recommending encryption algorithms.  Some critics charge that this is a conflict of interest, like putting the fox in charge of guarding the hen house.  NSA has been pushing a conventional encryption algorithm that they designed, and they won't tell anybody how it works because that's classified.  They want others to trust it and use it.  But any cryptographer can tell you that a well-designed encryption algorithm does not have to be classified to remain secure.  Only the keys should need protection.  How does anyone else really know if NSA's classified algorithm is secure?  It's not that hard for NSA to design an encryption algorithm that only they can crack, if no one else can review the algorithm.  Are they deliberately selling snake oil?

There are three main factors that have undermined the quality of commercial cryptographic software in the US.  The first is the virtually universal lack of competence of implementors of commercial encryption software (although this is starting to change since the publication of PGP).  Every software engineer fancies himself a cryptographer, which has led to the proliferation of really bad crypto software.  The second is the NSA deliberately and systematically suppressing all the good commercial encryption technology, by legal intimidation and economic pressure.  Part of this pressure is brought to bear by stringent export controls on encryption software which, by the economics of software marketing, has the net effect of suppressing domestic encryption software.  The other principle method of suppression comes from the granting all the software patents for all the public key encryption algorithms to a single company, affording a single choke point to suppress the spread

of this technology.  The net effect of all this is that before PGP was published, there was almost no highly secure general purpose encryption software available in the US.

I'm not as certain about the security of PGP as I once was about my brilliant encryption software from college.  If I were, that would be a bad sign.  But I'm pretty sure that PGP does not contain any glaring weaknesses (although it may contain bugs).  The crypto algorithms were developed by people at high levels of civilian cryptographic academia, and have been individually subject to extensive peer review.  Source code is available to facilitate peer review of PGP and to help dispel the fears of some users.  It's reasonably well researched, and has been years in the making.  And I don't work for the NSA.  I hope it doesn't require too large a "leap of faith" to trust the security of PGP.


Notice To Mac Users
Notice to Macintosh Users

=========================

PGP was originally developed for MSDOS and Unix machines.  There is also an Apple Macintosh version of PGP.  This manual is written for the MSDOS/Unix versions of PGP, which use a command-line interface for all the PGP functions.  On the Mac, all the PGP functions are accessed through pull-down menus and dialog boxes.  There is also on-line help on the Mac for how to use MacPGP, and there should be some Mac-specific user documentation included in the MacPGP release package, in addition to this manual.

Almost all good Mac software applications are written from scratch for the Mac, not simply ported there from other operating systems.  Unfortunately, the current Mac version of PGP was not designed for the Mac from scratch.  It was ported from the MSDOS/Unix version to the Mac by Zbigniew Fiedorwicz.  Since the MSDOS/Unix version of PGP was not designed for a GUI (graphical user interface), porting to the Mac was not an easy task, and many bugs still remain.  An all-new

version of PGP is under development, designed for easy adaptation to a GUI.  A new Mac version will be developed from this new PGP source code.  It will be more Mac-like, and more reliable.  Despite the bugs in the current version of MacPGP, it is important to note that if Zbigniew had waited for this all-new version of PGP to be developed before he ported PGP to the Mac, the world would have been deprived of a Mac version of PGP for far too long.


PGP DOS Quick Reference
PGP Quick Reference

===================

Here's a quick summary of PGP commands.

To encrypt a plaintext file with the recipient's public key:

     pgp -e textfile her_userid

To sign a plaintext file with your secret key:

     pgp -s textfile [-u your_userid]

To sign a plaintext ASCII text file with your secret key, producing a signed plaintext message suitable for sending via E-mail:

     pgp -sta textfile [-u your_userid]

To sign a plaintext file with your secret key, and then encrypt it with the recipient's public key:

     pgp -es textfile her_userid [-u your_userid]

To encrypt a plaintext file with just conventional cryptography, type:

     pgp -c textfile

To decrypt an encrypted file, or to check the signature integrity of a signed file:

     pgp ciphertextfile [-o plaintextfile]

To encrypt a message for any number of multiple recipients:

     pgp -e textfile userid1 userid2 userid3

--- Key management commands:

To generate your own unique public/secret key pair:

     pgp -kg

To add a public or secret key file's contents to your public or

secret key ring:

     pgp -ka keyfile [keyring]

To extract (copy) a key from your public or secret key ring:

     pgp -kx userid keyfile [keyring]

or:  pgp -kxa userid keyfile [keyring]

To view the contents of your public key ring:

     pgp -kv[v] [userid] [keyring]

To view the "fingerprint" of a public key, to help verify it over the telephone with its owner:

     pgp -kvc [userid] [keyring]

To view the contents and check the certifying signatures of your public key ring:

     pgp -kc [userid] [keyring]

To edit the userid or pass phrase for your secret key:

     pgp -ke userid [keyring]

To edit the trust parameters for a public key:

     pgp -ke userid [keyring]

To remove a key or just a userid from your public key ring:

     pgp -kr userid [keyring]

To sign and certify someone else's public key on your public key ring:

     pgp -ks her_userid [-u your_userid] [keyring]

To remove selected signatures from a userid on a keyring:

     pgp -krs userid [keyring]

To permanently revoke your own key, issuing a key compromise certificate:

     pgp -kd your_userid

To disable or reenable a public key on your own public key ring:

     pgp -kd userid

--- Esoteric commands:

To decrypt a message and leave the signature on it intact:

     pgp -d ciphertextfile

To create a signature certificate that is detached from the document:

     pgp -sb textfile [-u your_userid]

To detach a signature certificate from a signed message:

     pgp -b ciphertextfile

--- Command options that can be used in combination with other command options (sometimes even spelling interesting words!):

To produce a ciphertext file in ASCII radix-64 format, just add the

-a option when encrypting or signing a message or extracting a key:

     pgp -sea textfile her_userid

or:  pgp -kxa userid keyfile [keyring]

To wipe out the plaintext file after producing the ciphertext file, just add the -w (wipe) option when encrypting or signing a message:

     pgp -sew message.txt her_userid

To specify that a plaintext file contains ASCII text, not binary, and should be converted to recipient's local text line conventions, add the -t (text) option to other options:

     pgp -seat message.txt her_userid

To view the decrypted plaintext output on your screen (like the Unix-style "more" command), without writing it to a file, use the -m (more) option while decrypting:

     pgp -m ciphertextfile

To specify that the recipient's decrypted plaintext will be shown ONLY on her screen and cannot be saved to disk, add the -m option:

     pgp -steam message.txt her_userid

To recover the original plaintext filename while decrypting, add the -p option:

     pgp -p ciphertextfile

To use a Unix-style filter mode, reading from standard input and writing to standard output, add the -f option:

     pgp -feast her_userid <inputfile >outputfile


PGP Legal Issues
Legal Issues

============

For detailed information on PGP(tm) licensing, distribution, copyrights, patents, trademarks, liability limitations, and export controls, see the "Legal Issues" section in the "PGP User's Guide,

Volume II: Special Topics".

PGP uses a public key algorithm claimed by U.S. patent #4,405,829. The exclusive licensing rights to this patent are held by a company called Public Key Partners (PKP), and you may be infringing the patent if you use PGP in the USA without a license.  These issues are detailed in the Volume II manual, and in the RSAREF license that comes with the freeware version of PGP.  PKP has licensed others to practice the patent, including a company known as ViaCrypt, in Phoenix, Arizona.  ViaCrypt sells a fully licensed version of PGP.  ViaCrypt may be reached at 602-944-0773.

PGP is "guerrilla" freeware, and I don't mind if you distribute it widely.  Just don't ask me to send you a copy.  Instead, you can look for it yourself on many BBS systems and a number of Internet FTP sites.  But before you distribute PGP, it is essential that you understand the U.S. export controls on encryption software.


PGP Acknowledgments
Acknowledgments

================

Formidable obstacles and powerful forces have been arrayed to stop PGP.  Dedicated people are helping to overcome these obstacles.  PGP has achieved notoriety as "underground software", and bringing PGP "above ground" as fully licensed freeware has required patience and

persistence.  I'd especially like to thank Hal Abelson, Jeff Schiller, Brian LaMacchia, and Derek Atkins at MIT for their determined efforts.  I'd also like to thank Jim Bruce and David Litster in the MIT administration and Bob Prior and Terry Ehling at the MIT Press.  And I'd like to thank my entire legal defense team, whose job is not over yet.  I used to tell a lot of lawyer jokes, before I encountered so many positive examples of lawyers in my legal defense team, most of whom work pro bono.

The development of PGP has turned into a remarkable social phenomenon, whose unique political appeal has inspired the collective efforts of an ever-growing number of volunteer programmers.  Remember that children's story called "Stone Soup"?

I'd like to thank the following people for their contributions to the creation of Pretty Good Privacy.  Although I was the author of PGP  version 1.0, major parts of later versions of PGP were implemented by an international collaborative effort involving a large number of contributors, under my design guidance.

Branko Lankester, Hal Finney and Peter Gutmann all contributed a huge amount of time in adding features for PGP 2.0, and ported it to Unix  variants.

Hugh Kennedy ported it to VAX/VMS, Lutz Frank ported it to the Atari ST, and Cor Bosman and Colin Plumb ported it to the Commodore Amiga.

Translation of PGP into foreign languages was done by Jean-loup Gailly in France, Armando Ramos in Spain, Felipe Rodriquez Svensson and Branko Lankester in The Netherlands, Miguel Angel Gallardo in Spain, Hugh Kennedy and Lutz Frank in Germany, David Vincenzetti in Italy, Harry Bush and Maris Gabalins in Latvia, Zygimantas Cepaitis in Lithuania, Peter Suchkow and Andrew Chernov in Russia, and Alexander Smishlajev in Esperantujo.  Peter Gutmann offered to

translate it into New Zealand English, but we finally decided PGP could get by with US English.

Jean-loup Gailly, Mark Adler, and Richard B. Wales published the ZIP compression code, and granted permission for inclusion into PGP.  The MD5 routines were developed and placed in the public domain by Ron Rivest.  The IDEA(tm) cipher was developed by Xuejia Lai and James L.

Massey at ETH in Zurich, and is used in PGP with permission from Ascom-Tech AG.

Charlie Merritt originally taught me how to do decent multiprecision arithmetic for public key cryptography, and Jimmy Upton contributed a faster multiply/modulo algorithm.  Thad Smith implemented an even faster modmult algorithm.  Zhahai Stewart contributed a lot of useful ideas on PGP file formats and other stuff, including having more than one user ID for a key.  I heard the idea of introducers from Whit Diffie.  Kelly Goen did most of the work for the initial electronic publication of PGP 1.0.

Various contributions of coding effort also came from Colin Plumb, Derek Atkins, and Castor Fu.  Other contributions of effort, coding or otherwise, have come from Hugh Miller, Eric Hughes, Tim May, Stephan Neuhaus, and too many others for me to remember right now.  Zbigniew Fiedorwicz did the first Macintosh port.

Since the release of PGP 2.0, many other programmers have sent in patches and bug fixes and porting adjustments for other computers. There are too many to individually thank here.

Just as in the "Stone Soup" story, it is getting harder to peer through the thick soup to see the stone at the bottom of the pot that I dropped in to start it all off.


About The PGP Author
About the Author

================

Philip Zimmermann is a software engineer consultant with 19 years experience, specializing in embedded real-time systems, cryptography, authentication, and data communications.  Experience includes design and implementation of authentication systems for financial information networks, network data security, key management protocols, embedded real-time multitasking executives, operating systems, and local area networks.

Custom versions of cryptography and authentication products and public key implementations such as the NIST DSS are available from Zimmermann, as well as custom product development services.  His consulting firm's address is:

Boulder Software Engineering

3021 Eleventh Street

Boulder, Colorado 80304  USA

Phone: 303-541-0140 (10:00am - 7:00pm Mountain Time)

Fax: arrange by phone

Internet:  prz@acm.org


PGP Special Topics Overview
Phil's Pretty Good Software

Presents

=======

PGP(tm)

=======

Pretty Good(tm) Privacy

Public Key Encryption for the Masses

-------------------------

PGP(tm) User's Guide

Volume II: Special Topics

 -------------------------

by Philip Zimmermann

Revised  11 October 94

PGP Version 2.6.2 - 11 Oct 94

Software by

Philip Zimmermann, and many others.

Synopsis:  PGP(tm) uses public-key encryption to protect E-mail and  data files.  Communicate securely with people you've never met, with no secure channels needed for prior exchange of keys.  PGP is well featured and fast, with sophisticated key management, digital

signatures, data compression, and good ergonomic design.

Software and documentation (c) Copyright 1990-1994 Philip Zimmermann. All rights reserved.  For information on PGP licensing, distribution, copyrights, patents, trademarks, liability limitations, and export controls, see the "Legal Issues" section.  Distributed by the Massachusetts Institute of Technology.

Quick Overview

==============

Pretty Good(tm) Privacy (PGP), from Phil's Pretty Good Software, is a high security cryptographic software application for MSDOS, Unix, VAX/VMS, and other computers.  PGP combines the convenience of the Rivest-Shamir-Adleman (RSA) public key cryptosystem with the speed of

conventional cryptography, message digests for digital signatures, data compression before encryption, good ergonomic design, and sophisticated key management.

This volume II of the PGP User's Guide covers advanced topics about PGP that were not covered in the "PGP User's Guide, Volume I: Essential Topics".  You should first read the Essential Topics volume, or this manual won't make much sense to you.  Reading this Special Topics volume is optional, except for the legal issues section, which everyone should read.


Selectings Keys via Key ID

Selecting Keys via Key ID

-------------------------

In all commands that let the user type a user ID or fragment of a user ID to select a key, the hexadecimal key ID may be used instead. Just use the key ID, with a prefix of "0x", in place of the user ID.

For example:

    pgp -kv 0x67F7

This would display all keys that had 67F7 as part of their key IDs.

This feature is particularly useful if you have two different keys from the same person, with the same user ID.  You can unambiguously pick which key you want by specifying the key ID.


Separating Signatures from Messages

-----------------------------------

Normally, signature certificates are physically attached to the text they sign.  This makes it convenient in simple cases to check signatures.  It is desirable in some circumstances to have signature certificates stored separately from the messages they sign.  It is possible to generate signature certificates that are detached from the text they sign.  To do this, combine the 'b' (break) option with the 's' (sign) option.

For example:

    pgp -sb letter.txt

This example produces an isolated signature certificate in a file called "letter.sig".  The contents of letter.txt are not appended to the signature certificate.

After creating the signature certificate file (letter.sig in the above example), send it along with the original text file to the recipient.  The recipient must have both files to check the signature

integrity.  When the recipient attempts to process the signature file, PGP notices that there is no text in the same file with the signature and prompts the user for the filename of the text. Only then can PGP properly check the signature integrity.  If the recipient knows in advance that the signature is detached from the text file, she can specify both filenames on the command line:

    pgp letter.sig letter.txt

or: pgp letter letter.txt

PGP will not have to prompt for the text file name in this case.

A detached signature certificate is useful if you want to keep the signature certificate in a separate certificate log.  A detached signature of an executable program is also useful for detecting a

subsequent virus infection.  It is also useful if more than one party must sign a document such as a legal contract, without nesting signatures.  Each person's signature is independent.

If you receive a ciphertext file that has the signature certificate glued to the message, you can still pry the signature certificate away from the message during the decryption.  You can do this with

the -b option during decrypt, like so:

    pgp -b letter

This decrypts the letter.pgp file and if there is a signature in it, PGP checks the signature and detaches it from the rest of the message, storing it in the file letter.sig.


Decrypting A Message and Leaving The Segnature

Decrypting the Message and Leaving the Signature on it

------------------------------------------------------

Usually, you want PGP to completely unravel a ciphertext file, decrypting it and checking the nested signature if there is one, peeling away the layers until you are left with only the original

plaintext file.

But sometimes you want to decrypt an encrypted file, and leave the inner signature still attached, so that you are left with a decrypted signed message.  This may be useful if you want to send a copy of a signed document to a third party, perhaps re-enciphering it.  For example, suppose you get a message signed by Charlie, encrypted to you.  You want to decrypt it, and, leaving Charlie's signature on it, you want to send it to Alice, perhaps re-enciphering it with Alice's public key.  No problem.  PGP can handle that.

To simply decrypt a message and leave the signature on it intact, type:

    pgp -d letter

This decrypts letter.pgp, and if there is an inner signature, it is left intact with the decrypted plaintext in the output file.

Now you can archive it, or maybe re-encrypt it and send it to someone else.


Sending ASCII Text Files Across Diff. Environments

Sending ASCII Text Files Across Different Machine Environments

--------------------------------------------------------------

You may use PGP to encrypt any kind of plaintext file, binary 8-bit data or ASCII text.  Probably the most common usage of PGP will be for E-mail, when the plaintext is ASCII text.

ASCII text is sometimes represented differently on different machines.  For example, on an MSDOS system, all lines of ASCII text are terminated with a carriage return followed by a linefeed.  On a Unix system, all lines end with just a linefeed.  On a Macintosh, all lines end with just a carriage return.  This is a sad fact of life.

Normal unencrypted ASCII text messages are often automatically translated to some common "canonical" form when they are transmitted from one machine to another.  Canonical text has a carriage return and a linefeed at the end of each line of text.  For example, the popular KERMIT communication protocol can convert text to canonical form when transmitting it to another system.  This gets converted back to local text line terminators by the receiving KERMIT.  This makes it easy to share text files across different systems.

But encrypted text cannot be automatically converted by a communication protocol, because the plaintext is hidden by encipherment.  To remedy this inconvenience, PGP lets you specify that the plaintext should be treated as ASCII text (not binary data) and should be converted to canonical text form before it gets encrypted.  At the receiving end, the decrypted plaintext is automatically converted back to whatever text form is appropriate for the local environment.

To make PGP assume the plaintext is text that should be converted to canonical text before encryption, just add the "t" option when encrypting or signing a message, like so:

   pgp -et message.txt her_userid

This mode is automatically turned off if PGP detects that the plaintext file contains what it thinks is non-text binary data.

If you need to use the -t option a lot, you can just turn on the TEXTMODE flag in the PGP configuration file.  That's what I do.

For PGP users that use non-English 8-bit character sets, when PGP  converts text to canonical form, it may convert data from the local character set into the LATIN1 (ISO 8859-1 Latin Alphabet 1) character set, depending on the setting of the CHARSET parameter in the PGP

configuration file.  LATIN1 is a superset of ASCII, with extra characters added for many European languages.


Using PGP as a Better Uuencode

------------------------------

A lot of people in the Unix world send binary data files through E-mail channels by using the Unix "uuencode" utility to convert the file into printable ASCII characters that can be sent via email.  No

encryption is involved, so neither the sender nor the recipient need any special keys.  The uuencode format was designed for a similar purpose as PGP's radix-64 ASCII transport armor format described in the "Sending Ciphertext Through E-mail Channels: Radix-64 Format" section, but not as good.  A different radix-64 character set is used.  Uuencode has its problems, such as 1) several slightly

incompatible character sets for different versions of uuencode in the MSDOS and Unix worlds, and 2) the data can be corrupted by some E-mail gateways that strip trailing blanks or do other modifications

to the character set used by uuencode.

PGP may be used in a manner that offers the same general features as uuencode, and then some.  You can get PGP to just convert a file into PGP's radix-64 ASCII transport armor format, but you don't have to encrypt the file or sign it, so no keys are needed by either party. Simply use the -a option alone.

For example:

    pgp -a filename

This would produce a radix-64 armored file called "filename.asc".

If you read the "Sending Ciphertext Through E-mail Channels: Radix-64 Format" section, you will see that PGP's approach offers several important advantages over the uuencode approach:

 * PGP will break big files up into chunks small enough to E-mail.

 * PGP will append a CRC error detection code to each chunk.

 * PGP will attempt to compress the data before converting it to radix-64 armor.

 * PGP's radix-64 character set is more resilient to E-mail character conversions than the one used by                                uuencode.

 * Text files can be converted by the sender to canonical text  format, as explained in the "Sending ASCII Text Files Across Different Machine Environments" section.

The recipient can restore the sender's original filename by unwrapping the message with PGP's -p option.  You can use "pgp -a" in any situation in which you could have used uuencode, if the recipient also has PGP.  PGP is a better uuencode than uuencode.


Leaving No Traces on Disk

Leaving No Traces of Plaintext on the Disk

------------------------------------------

After PGP makes a ciphertext file for you, you can have PGP automatically overwrite the plaintext file and delete it, leaving no trace of plaintext on the disk so that no one can recover it later

using a disk block scanning utility.  This is useful if the plaintext file contains sensitive information that you don't want to keep around.

To wipe out the plaintext file after producing the ciphertext file, just add the "w" (wipe) option when encrypting or signing a message, like so:

    pgp -esw message.txt her_userid

This example creates the ciphertext file "message.pgp", and the plaintext file "message.txt" is destroyed beyond recovery.

Obviously, you should be careful with this option.  Also note that this will not wipe out any fragments of plaintext that your word processor might have created on the disk while you were editing the message before running PGP.  Most word processors create backup files, scratch files, or both.  Also, it overwrites the file only once, which is enough to thwart conventional disk recovery efforts,

but not enough to withstand a determined and sophisticated effort to recover the faint magnetic traces of the data using special disk recovery hardware.


Displaying Decrypted Plaintext on Your Screen

---------------------------------------------

To view the decrypted plaintext output on your screen (like the Unix-style "more" command), without writing it to a file, use the -m (more) option while decrypting:

     pgp -m ciphertextfile

This displays the decrypted plaintext display on your screen one screen full at a time.


Making a Message For Her Eyes Only

----------------------------------

To specify that the recipient's decrypted plaintext will be shown ONLY on her screen and will not be saved to disk, add the -m option:

     pgp -sem message.txt her_userid

Later, when the recipient decrypts the ciphertext with her secret key and pass phrase, the plaintext will be displayed on her screen but will not be saved to disk.  The text will be displayed as it would if she used the Unix "more" command, one screenful at a time.  If she wants to read the message again, she will have to decrypt the ciphertext again.

This feature is the safest way for you to prevent your sensitive message from being inadvertently left on the recipient's disk.  This feature was added at the request of a user who wanted to send intimate messages to his lover, but was afraid she might accidentally leave the decrypted messages on her husband's computer.

Note that this feature will not prevent a clever and determined person from finding a way to save the decrypted plaintext to disk-- it's to help prevent a casual user from doing it inadvertently.


Preserving The Original Filename

Preserving the Original Plaintext Filename

------------------------------------------

Normally, PGP names the decrypted plaintext output file with a name similar to the input ciphertext filename, but dropping the extension.  Or, you can override that convention by specifying an

output plaintext filename on the command line with the -o option. For most E-mail, this is a reasonable way to name the plaintext file, because you get to decide its name when you decipher it, and your

typical E-mail messages often come from useless original plaintext filenames like "to_phil.txt".

But when PGP encrypts a plaintext file, it always saves the original filename and attaches it to the plaintext before it compresses and encrypts the plaintext.  Normally, this hidden original filename is discarded by PGP when it decrypts, but you can tell PGP you want to preserve the original plaintext filename and use it as the name of the decrypted plaintext output file.  This is useful if PGP is used

on files whose names are important to preserve.

To recover the original plaintext filename while decrypting, add the -p option, like so:

     pgp -p ciphertextfile

I usually don't use this option, because if I did, about half of my incoming E-mail would decrypt to the same plaintext filenames of "to_phil.txt" or "prz.txt".


Editing Your User ID or Pass Phrase

-----------------------------------

Sometimes you may need to change your pass phrase, perhaps because someone looked over your shoulder while you typed it in.

Or you may need to change your user ID, because you got married and changed your name, or maybe you changed your E-mail address.  Or maybe you want to add a second or third user ID to your key, because you may be known by more than one name or E-mail address or job title.  PGP lets you attach more than one user ID to your key, any one of which may be used to look up your key on the key ring.

To edit your own userid or pass phrase for your secret key:

     pgp -ke userid [keyring]

PGP prompts you for a new user ID or a new pass phrase.

If you edit your user ID, PGP actually adds a new user ID, without deleting the old one.  If you want to delete an old user ID, you will have to do that in a separate operation.

The optional [keyring] parameter, if specified, must be a public keyring, not a secret keyring.  The userid field must be your own userid, which PGP knows is yours because it appears on both your

public keyring and your secret keyring.  Both key rings will be updated, even though you only specified the public key ring.

The -ke command works differently depending on whether you use it on a public or secret key.  It can also be used to edit the trust parameters for a public key.


Editing Trust Parameters

Editing the Trust Parameters for a Public Key

---------------------------------------------

Sometimes you need to alter the trust parameters for a public key on your public key ring.  For a discussion on what these trust parameters mean, see the section "How Does PGP Keep Track of Which Keys are Valid?" in the Essential Topics volume of the PGP User's Guide.

To edit the trust parameters for a public key:

     pgp -ke userid [keyring]

The optional [keyring] parameter, if specified, must be a public keyring, not a secret keyring.


Checking Your Public Key Ring

Checking If Everything is OK on Your Public Key Ring

----------------------------------------------------

Normally, PGP automatically checks any new keys or signatures on your public key ring and updates all the trust parameters and validity scores.  In theory, it keeps all the key validity status information up to date as material is added to or deleted from your public key ring.  But perhaps you may want to explicitly force PGP to perform a comprehensive analysis of your public key ring, checking all the certifying signatures, checking the trust parameters, updating all the validity scores, and checking your own ultimately-trusted key against a backup copy on a write-protected floppy disk.  It may be a good idea to do this hygienic maintenance periodically to make sure nothing is wrong with your public key ring.  To force PGP to perform a full analysis of your public key ring, use the -kc (key ring check) command:

     pgp -kc

You can also make PGP check all the signatures for just a single

selected public key by:

     pgp -kc userid [keyring]

For further information on how the backup copy of your own key is checked, see the description of the BAKRING parameter in the configuration file section of this manual.


Verifying a Public Key Over the Phone

-------------------------------------

If you get a public key from someone that is not certified by anyone you trust, how can you tell if it's really their key?  The best way to verify an uncertified key is to verify it over some independent

channel other than the one you received the key through.  One convenient way to tell, if you know this person and would recognize them on the phone, is to call them and verify their key over the

telephone.  Rather than reading their whole tiresome (ASCII-armored) key to them over the phone, you can just read their key's "fingerprint" to them.  To see this fingerprint, use the -kvc command:

     pgp -kvc userid [keyring]

This will display the key with the 16-byte digest of the public key components.  Read this 16-byte fingerprint to the key's owner on the phone, while she checks it against her own, using the same -kvc command at her end.

You can both verify each other's keys this way, and then you can sign each other's keys with confidence.  This is a safe and convenient way to get the key trust network started for your circle of friends.

Note that sending a key fingerprint via E-mail is not the best way to verify the key, because E-mail can be intercepted and modified.  It's best to use a different channel than the one that was used to send the key itself.  A good combination is to send the key via E-mail, and the key fingerprint via a voice telephone conversation.  Some people distribute their key fingerprint on their business cards,

which looks really cool.

For current versions of PGP, the key fingerprint is computed using the MD5 hash function.  A future version of PGP will optionally use a new and different hash function, SHA, instead of MD5.

If you don't know me, please don't call me to verify my key over the phone-- I get too many calls like that.  Since every PGP user has a copy of my public key, no one could tamper with all the copies that are out there.  The discrepancy would soon be noticed by someone who checked it from more than one source, and word would soon get out on the Internet.

For those of you who want to verify my public key (included in the standard PGP release package), here are the particulars:

  UserID: "Philip R. Zimmermann <prz@acm.org>"

  Key Size: 1024 bits;  Creation date: 21 May 1993;  KeyID: C7A966DD

  Key fingerprint:  9E 94 45 13 39 83 5F 70  7B E7 D8 ED C4 BE 5A A6

The information printed above conceivably could still be tampered with in the electronic distribution of the PGP User's Guide.  But if you read this in the printed version of the manual, available in bookstores from MIT Press, it's a safe bet that it really is my own key's fingerprint.


Handling Large Public Key Rings

------------------------------

PGP was originally designed for handling small personal key rings for keeping all your friends on, like a personal rolodex.  A couple hundred keys is a reasonable size for such a keyring.  But as PGP has become more popular, people are now trying to add other large key rings to their own keyring.  Sometimes this involves adding thousands of keys to your keyring.  PGP, in its present form, cannot perform this operation in a reasonable period of time, while you wait at your keyboard.  Not for huge key rings.

You may want to add a huge "imported" keyring to your own keyring, because you are only interested in a few dozen keys on the bigger keyring you are bringing in.  If that's all you want from the other keyring, it would be more efficient if you extract the few keys you need from the big foreign keyring, and then add just these few keys to your own keyring.  Use the -kx command to extract them from the foreign keyring, specifying the keyring name on the command line. Then add these extracted keys to your own keyring.

The real solution is to improve PGP to use advanced database techniques to manage large key rings efficiently.  We are working on this, and should have it done Real Soon Now.  Until this happens, you will just have to use smaller key rings, or be patient.


Using PGP as a Unix-style Filter

--------------------------------

Unix fans are accustomed to using Unix "pipes" to make two applications work together.  The output of one application can be directly fed through a pipe to be read as input to another application.  For this to work, the applications must be capable of reading the raw material from "standard input" and writing the finished output to "standard output".  PGP can operate in this mode. If you don't understand what this means, then you probably don't need this feature.

To use a Unix-style filter mode, reading from standard input and writing to standard output, add the -f option, like so:

     pgp -feast her_userid <inputfile >outputfile

This feature makes it easier to make PGP work with electronic mail applications.

When using PGP in filter mode to decrypt a ciphertext file, you may find it useful to use the PGPPASS environmental variable to hold the pass phrase, so that you won't be prompted for it.  The PGPPASS feature is explained below.


Suppressing Unnecessary Questions

Suppressing Unnecessary Questions:  BATCHMODE

----------------------------------------------

With the BATCHMODE flag enabled on the command line, PGP will not ask any unnecessary questions or prompt for alternate filenames.  Here is an example of how to set this flag:

    pgp +batchmode cipherfile

This is useful for running PGP non-interactively from Unix shell scripts or MSDOS batch files.  Some key management commands still need user interaction even when BATCHMODE is on, so shell scripts may need to avoid them.

BATCHMODE may also be enabled to check the validity of a signature on a file.  If there was no signature on the file, the exit code is 1.  If it had a signature that was good, the exit code is 0.


Force "YES" Answers To Confirmation Questions

Force "Yes" Answer to Confirmation Questions:  FORCE

----------------------------------------------------

This command-line flag makes PGP assume "yes" for the user response to the confirmation request to overwrite an existing file, or when removing a key from the keyring via the -kr command.  Here is an example of how to set this flag:

    pgp +force cipherfile

or:

    pgp -kr +force Smith

This feature is useful for running PGP non-interactively from a Unix shell script or MSDOS batch file.


PGP Exit Codes for Shell

PGP Returns Exit Status to the Shell

------------------------------------

To facilitate running PGP in "batch" mode, such as from an MSDOS ".bat" file or from a Unix shell script, PGP returns an error exit status to the shell.  An exit status code of zero means normal exit, while a nonzero exit status indicates some kind of error occurred. Different error exit conditions return different exit status codes to the shell.


Environmental Variable for Pass Phrase

--------------------------------------

Normally, PGP prompts the user to type a pass phrase whenever PGP needs a pass phrase to unlock a secret key.  But it is possible to store the pass phrase in an environmental variable from your operating system's command shell.  The environmental variable PGPPASS can be used to hold the pass phrase that PGP will attempt to use first.  If the pass phrase stored in PGPPASS is incorrect, PGP recovers by prompting the user for the correct pass phrase.

For example, on MSDOS, the shell command:

    SET PGPPASS=zaphod beeblebrox for president

would eliminate the prompt for the pass phrase if the pass phrase were indeed "zaphod beeblebrox for president".

This dangerous feature makes your life more convenient if you have to regularly deal with a large number of incoming messages addressed to your secret key, by eliminating the need for you to repeatedly type in your pass phrase every time you run PGP.

I added this feature because of popular demand.  However, this is a somewhat dangerous feature, because it keeps your precious pass phrase stored somewhere other than just in your brain.  Even worse, if you are particularly reckless, it may even be stored on a disk on the same computer as your secret key.  It would be particularly dangerous and stupid if you were to install this command in a batch or script file, such as the MSDOS AUTOEXEC.BAT file.  Someone could come along on your lunch hour and steal both your secret key ring and the file containing your pass phrase.

I can't emphasize the importance of this risk enough.  If you are contemplating using this feature, be sure to read the sections "Exposure on Multi-user Systems" and "How to Protect Secret Keys from Disclosure" in this volume and in the Essential Topics volume of the PGP User's Guide.

If you must use this feature, the safest way to do it would be to just manually type in the shell command to set PGPPASS every time you boot your machine to start using PGP, and then erase it or turn off your machine when you are done.  And you should definitely never do it in an environment where someone else may have access to your machine.  Someone could come along and simply ask your computer to display the contents of PGPPASS.

Sometimes you want to pass the pass phrase into PGP from another application, such as an E-mail package.  In some cases, it may not always be desirable to use the PGPPASS variable for that purpose. There is another way to pass your pass phrase into PGP from another application.  Use the "-z" command line option.  This option is designed primarily for invoking PGP from inside an E-mail package. The pass phrase follows the -z option on the command line.  There are risks associated with using this approach, similar to those risks described above for using the PGPPASS variable.


PGP DOS Configurations Settings
Setting Parameters in the PGP Configuration File

================================================

PGP has a number of user-settable parameters that can be defined in a special PGP configuration text file called "config.txt", in the directory pointed to by the shell environmental variable PGPPATH. Having a configuration file enables the user to define various flags and parameters for PGP without the burden of having to always define these parameters in the PGP command line.

The filename "config.txt" has been in use for a long time by PGP, but some folks have pointed out that it may be at odds with naming conventions for configuration files for specific operating systems. Accordingly, PGP now tries to open this filename only after first trying to open the file ".pgprc" on Unix platforms, and "pgp.ini" on other platforms, in the same directory that PGP would look for "config.txt".

Configuration parameters may be assigned integer values, character string values, or on/off values, depending on what kind of configuration parameter it is.  A sample configuration file is

provided with PGP, so you can see some examples.

In the configuration file, blank lines are ignored, as is anything following the '#' comment character.  Keywords are not case-sensitive.

Here is a short sample fragment of a typical configuration file:

   # TMP is the directory for PGP scratch files, such as a RAM disk.

   TMP = "e:\"    # Can be overridden by environment variable TMP.

   Armor = on     # Use -a flag for ASCII armor whenever applicable.

   # CERT_DEPTH is how deeply introducers may introduce introducers.

   cert_depth = 3

If some configuration parameters are not defined in the configuration file, or if there is no configuration file, or if PGP can't find the configuration file, the values for the configuration parameters

default to some reasonable value.

Note that it is also possible to set these same configuration parameters directly from the PGP command line, by preceding the parameter setting with a "+" character.  For example, the following

two PGP commands produce the same effect:

     pgp -e +armor=on message.txt smith

or:  pgp -ea message.txt smith


TMP-Temporary Files

TMP - Directory Pathname for Temporary Files

--------------------------------------------

Default setting:  TMP = ""

The configuration parameter TMP specifies what directory to use for PGP's temporary scratch files.  The best place to put them is on a RAM disk, if you have one.  That speeds things up quite a bit, and increases security somewhat.  If TMP is undefined, the temporary files go in the current directory.  If the shell environmental variable TMP is defined, PGP instead uses that to specify where the temporary files should go.


Foreign Language Selector

LANGUAGE - Foreign Language Selector

------------------------------------

Default setting:  LANGUAGE = "en"

PGP displays various prompts, warning messages, and advisories to the user on the screen.  For example, messages such as "File not found.", or "Please enter your pass phrase:".  These messages are normally in English.  But it is possible to get PGP to display its messages to the user in other languages, without having to modify the PGP executable program.

A number of people in various countries have translated all of PGP's display messages, warnings, and prompts into their native languages.  These hundreds of translated message strings have been placed in a special text file called "language.txt", distributed with the PGP release.  The messages are stored in this file in English, Spanish, Dutch, German, French, Italian, Russian, Latvian, and Lithuanian. Other languages may be added later.

 The configuration parameter LANGUAGE specifies what language to display these messages in.  LANGUAGE may be set to "en" for English, "es" for Spanish, "de" for German, "nl" for Dutch, "fr" for French, "it" for Italian, "ru" for Russian, "lt3" for Lithuanian, "lv" for Latvian, "esp" for Esperanto.  For example, if this line appeared in the configuration file:

   LANGUAGE = "fr"

PGP would select French as the language for its display messages. The default setting is English.

When PGP needs to display a message to the user, it looks in the "language.txt" file for the equivalent message string in the selected foreign language and displays that translated message to the user. If PGP can't find the language string file, or if the selected language is not in the file, or if that one phrase is not translated into the selected language in the file, or if that phrase is missing

entirely from the file, PGP displays the message in English.

To conserve disk space, most foreign translations are not included in the standard PGP release package, but are available separately.


Default User ID For Making Signatures

MYNAME - Default User ID for Making Signatures

----------------------------------------------

Default setting:  MYNAME = ""

The configuration parameter MYNAME specifies the default user ID to use to select the secret key for making signatures.  If MYNAME is not defined, the most recent secret key you installed on your secret key ring will be used.  The user may also override this setting by specifying a user ID on the PGP command line with the -u option.


Assuming Plain Text is a Text File

TEXTMODE - Assuming Plaintext is a Text File

--------------------------------------------

Default setting:  TEXTMODE = off

The configuration parameter TEXTMODE is equivalent to the -t command line option.  If enabled, it causes PGP to assume the plaintext is a text file, not a binary file, and converts it to "canonical text" before encrypting it.  Canonical text has a carriage return and a linefeed at the end of each line of text.

This mode will be automatically turned off if PGP detects that the plaintext file contains what it thinks is non-text binary data.  If you intend to use PGP primarily for E-mail purposes, you should turn

TEXTMODE=ON.

For VAX/VMS systems, the current version of PGP defaults TEXTMODE=ON.

For further details, see the section "Sending ASCII Text Files Across Different Machine Environments".


Specific Local Character Sets For Text Files

CHARSET - Specifies Local Character Set for Text Files

------------------------------------------------------

Default setting:  CHARSET = NOCONV

Because PGP must process messages in many non-English languages with non-ASCII character sets, you may have a need to tell PGP what local character set your machine uses.  This determines what character conversions are performed when converting plaintext files to and from

canonical text format.  This is only a concern if you are in a non-English non-ASCII environment.

The configuration parameter CHARSET selects the local character set. The choices are NOCONV (no conversion), LATIN1 (ISO 8859-1 Latin Alphabet 1), KOI8 (used by most Russian Unix systems), ALT_CODES (used by Russian MSDOS systems), ASCII, and CP850 (used by most

western European languages on standard MSDOS PCs). LATIN1 is the internal representation used by PGP for canonical text, so if you select LATIN1, no conversion is done.  Note also that PGP

treats KOI8 as LATIN1, even though it is a completely different character set (Russian), because trying to convert KOI8 to either LATIN1 or CP850 would be futile anyway.  This means that setting CHARSET to NOCONV, LATIN1, or KOI8 are all equivalent to PGP.

If you use MSDOS and expect to send or receive traffic in western European languages, set CHARSET = "CP850".  This will make PGP convert incoming canonical text messages from LATIN1 to CP850 after decryption.  If you use the -t (textmode) option to convert to canonical text, PGP will convert your CP850 text to LATIN1 before encrypting it.

For further details, see the section "Sending ASCII Text Files Across Different Machine Environments".


Enable ASCII Armor Output

ARMOR - Enable ASCII Armor Output

---------------------------------

Default setting:  ARMOR = off

The configuration parameter ARMOR is equivalent to the -a command line option.  If enabled, it causes PGP to emit ciphertext or keys in ASCII Radix-64 format suitable for transporting through E-mail channels.  Output files are named with the ".asc" extension.

If you intend to use PGP primarily for E-mail purposes, you should turn ARMOR=ON.

For further details, see the section "Sending Ciphertext Through E-mail Channels: Radix-64 Format" in the Essential Topics volume.


Size of ASCII Armor Multipart Files

ARMORLINES - Size of ASCII Armor Multipart Files

------------------------------------------------

Default setting:  ARMORLINES = 720

When PGP creates a very large ".asc" radix-64 file for sending ciphertext or keys through the E-mail, it breaks the file up into separate chunks small enough to send through Internet mail

utilities.  Normally, Internet mailers prohibit files larger than about 50000 bytes, which means that if we restrict the number of lines to about 720, we'll be well within the limit.  The file chunks are named with suffixes ".as1", ".as2", ".as3", ...

The configuration parameter ARMORLINES specifies the maximum number of lines to make each chunk in a multipart ".asc" file sequence.  If you set it to zero, PGP will not break up the file into chunks.

Fidonet E-mail files usually have an upper limit of about 32K bytes, so 450 lines would be appropriate for Fidonet environments.

For further details, see the section "Sending Ciphertext Through E-mail Channels: Radix-64 Format" in the Essential Topics volume.


Keep Binary Ciphertext Files After Decrypting

KEEPBINARY - Keep Binary Ciphertext Files After Decrypting

----------------------------------------------------------

Default setting:  KEEPBINARY = off

When PGP reads a ".asc" file, it recognizes that the file is in radix-64 format and will convert it back to binary before processing as it normally does, producing as a by-product a ".pgp" ciphertext

file in binary form.  After further processing to decrypt the ".pgp" file, the final output file will be in normal plaintext form.

You may want to delete the binary ".pgp" intermediate file, or you may want PGP to delete it for you automatically.  You can still rerun PGP on the original ".asc" file.

The configuration parameter KEEPBINARY enables or disables keeping the intermediate ".pgp" file during decryption.

For further details, see the section "Sending Ciphertext Through E-mail Channels: Radix-64 Format" in the Essential Topics volume.


Enable Compression In DOS

COMPRESS - Enable Compression

-----------------------------

Default setting:  COMPRESS = on

The configuration parameter COMPRESS enables or disables data compression before encryption.  It is used mainly for debugging PGP. Normally, PGP attempts to compress the plaintext before it encrypts it.  Generally, you should leave this alone and let PGP attempt to

compress the plaintext.


Number Of Completely Trusted Intro.

COMPLETES_NEEDED - Number of Completely Trusted Introducers Needed

------------------------------------------------------------------

Default setting:  COMPLETES_NEEDED = 1

The configuration parameter COMPLETES_NEEDED specifies the minimum number of completely trusted introducers required to fully certify a public key on your public key ring.  This gives you a way of tuning PGP's skepticism.

For further details, see the section "How Does PGP Keep Track of  Which Keys are Valid?" in the Essential Topics volume.


Number Of Marginally Trusted Intro.

MARGINALS_NEEDED - Number of Marginally Trusted Introducers Needed

------------------------------------------------------------------

Default setting:  MARGINALS_NEEDED = 2

The configuration parameter MARGINALS_NEEDED specifies the minimum number of marginally trusted introducers required to fully certify a public key on your public key ring.  This gives you a way of tuning PGP's skepticism.

For further details, see the section "How Does PGP Keep Track of  Which Keys are Valid?" in the Essential Topics volume.


How Deep May Intros. Be Nested

CERT_DEPTH - How Deep May Introducers Be Nested

-----------------------------------------------

Default setting:  CERT_DEPTH = 4

The configuration parameter CERT_DEPTH specifies how many levels deep you may nest introducers to certify other introducers to certify public keys on your public key ring.  For example, If CERT_DEPTH is set to 1, there may only be one layer of introducers below your own ultimately-trusted key.  If that were the case, you would be required to directly certify the public keys of all trusted introducers on your key ring.  If you set CERT_DEPTH to 0, you could have no introducers at all, and you would have to directly certify each and every key on your public key ring in order to use it.  The minimum CERT_DEPTH is 0, the maximum is 8.

For further details, see the section "How Does PGP Keep Track of  Which Keys are Valid?" in the Essential Topics volume.


File Name For Backup Secret Keyring

BAKRING - Filename for Backup Secret Keyring

--------------------------------------------

Default setting:  BAKRING = ""

All of the key certification that PGP does on your public key ring ultimately depends on your own ultimately-trusted public key (or keys).  To detect any tampering of your public key ring, PGP must check that your own key has not been tampered with.  To do this, PGP must compare your public key against a backup copy of your secret key on some tamper-resistant media, such as a write-protected floppy disk.  A secret key contains all the information that your public key has, plus some secret components.  This means PGP can check your public key against a backup copy of your secret key.

The configuration parameter BAKRING specifies what pathname to use for PGP's trusted backup copy of your secret key ring.  On MSDOS, you could set it to "a:\secring.pgp" to point it at a write-protected backup copy of your secret key ring on your floppy drive.  This check is performed only when you execute the PGP -kc option to check your whole public key ring.

If BAKRING is not defined, PGP will not check your own key against any backup copy.

For further details, see the sections "How to Protect Public Keys from Tampering" and "How Does PGP Keep Track of Which Keys are Valid?" in the Essential Topics volume.


File Name Of Your Public Keyring

PUBRING - Filename for Your Public Keyring

------------------------------------------

Default setting:  PUBRING = "$PGPPATH/pubring.pgp"

You may want to keep your public keyring in a directory separate from your PGP configuration file in the directory specified by your $PGPPATH environmental variable.  You may specify the full path and filename for your public keyring by setting the PUBRING parameter.

For example, on an MSDOS system, you might want to keep your public keyring on a floppy disk by:

   PUBRING = "a:pubring.pgp"

 This feature is especially handy for specifying an alternative keyring on the command line.


File Name Of Secret Keyring

SECRING - Filename for Your Secret Keyring

------------------------------------------

Default setting:  SECRING = "$PGPPATH/secring.pgp"

You may want to keep your secret keyring in a directory separate from your PGP configuration file in the directory specified by your $PGPPATH environmental variable.  This comes in handy for putting your secret keyring in a directory or device that is more protected than your public keyring.  You may specify the full path and filename for your secret keyring by setting the SECRING parameter.  For example, on an MSDOS system, you might want to keep your secret keyring on a floppy disk by:

   SECRING = "a:secring.pgp"


File Name For Random Number Seed

RANDSEED - Filename for Random Number Seed

------------------------------------------

Default setting:  RANDSEED = "$PGPPATH/randseed.bin"

You may want to keep your random number seed file (for generation of session keys) in a directory separate from your PGP configuration file in the directory specified by your $PGPPATH environmental variable.  This comes in handy for putting your random number seed file in a directory or device that is more protected than your public keyring.  You may specify the full path and filename for your random seed file by setting the RANDSEED parameter.  For example, on an MSDOS system,

you might want to keep it on a floppy disk by:

   RANDSEED = "a:randseed.bin"


Select Shell Output

PAGER - Selects Shell Command to Display Plaintext Output

---------------------------------------------------------

Default setting:  PAGER = ""

PGP lets you view the decrypted plaintext output on your screen (like the Unix-style "more" command), without writing it to a file, if you use the -m (more) option while decrypting.  This displays the decrypted plaintext display on your screen one screenfull at a time.

If you prefer to use a fancier page display utility, rather than PGP's built-in one, you can specify the name of a shell command that PGP will invoke to display your plaintext output file.  The configuration parameter PAGER specifies the shell command to invoke to display the file.  For example, on MSDOS systems, you might want to use the popular shareware program "list.com" to display your plaintext message.  Assuming you have a copy of "list.com", you may set PAGER accordingly:

   PAGER = "list"

However, if the sender specified that this file is for your eyes only, and may not be written to disk, PGP always uses its own built-in display function.

For further details, see the section "Displaying Decrypted Plaintext  on Your Screen".


Show Pass Phrase To User

SHOWPASS - Echo Pass Phrase to User

-----------------------------------

Default setting:  SHOWPASS = off

Normally, PGP does not let you see your pass phrase as you type it in.  This makes it harder for someone to look over your shoulder while you type and learn your pass phrase.  But some typing-impaired people have problems typing their pass phrase without seeing what they are typing, and they may be typing in the privacy of their own homes.  So they asked if PGP can be configured to let them see what they type when they type in their pass phrase.

The configuration parameter SHOWPASS enables PGP to echo your typing during pass phrase entry.


Time Zone Adjustment In DOS

TZFIX - Time Zone Adjustment

---------------------------

Default setting:  TZFIX = 0

PGP provides time stamps for keys and signature certificates in Greenwich Mean Time (GMT), or Coordinated Universal Time (UTC), which means the same thing for our purposes.  When PGP asks the system for the time of day, the system is supposed to provide it in GMT.

But sometimes, because of improperly configured MSDOS systems, the system time is returned in US Pacific Standard Time plus 8 hours.  Sounds weird, doesn't it?  Perhaps because of some sort of US west-coast jingoism, MSDOS presumes local time is US Pacific time, and pre-corrects Pacific time to GMT.  This adversely affects the behavior of the internal MSDOS GMT time function that PGP calls.  However, if your MSDOS environmental variable TZ is already properly

defined for your time zone, this corrects the misconception MSDOS has that the whole world lives on the US west coast.

The configuration parameter TZFIX specifies the number of hours to add to the system time function to get GMT, for GMT time stamps on keys and signatures.  If the MSDOS environmental variable TZ is defined properly, you can leave TZFIX=0.  Unix systems usually shouldn't need to worry about setting TZFIX at all.  But if you are using some other obscure operating system that doesn't know about GMT, you may have to use TZFIX to adjust the system time to GMT.

On MSDOS systems that do not have TZ defined in the environment, you should make TZFIX=0 for California, -1 for Colorado, -2 for Chicago, -3 for New York, -8 for London, -9 for Amsterdam.  In the summer, TZFIX should be manually decrement from these values.  What a mess.

It would be much cleaner to set your MSDOS environmental variable TZ in your AUTOEXEC.BAT file, and not use the TZFIX correction.  Then MSDOS gives you good GMT time stamps, and will handle daylight savings time adjustments for you.  Here are some sample lines to insert into AUTOEXEC.BAT, depending on your time zone:

For Los Angeles:  SET TZ=PST8PDT

For Denver:       SET TZ=MST7MDT

For Arizona:      SET TZ=MST7

   (Arizona never uses daylight savings time)

For Chicago:      SET TZ=CST6CDT

For New York:     SET TZ=EST5EDT

For London:       SET TZ=GMT0BST

For Amsterdam:    SET TZ=MET-1DST

For Moscow:       SET TZ=MSK-3MSD

For Auckland:      SET TZ=NZT-13


Enable Clear Text

CLEARSIG - Enable Signed Messages to be Encapsulated as Clear Text

------------------------------------------------------------------

Default setting:  CLEARSIG = on

Normally, unencrypted PGP signed messages have a signature certificate prepended in binary form.  Also, the signed message is compressed, rendering the message unreadable to casual human eyes, even though the message is not actually encrypted.  To send this binary data through a 7-bit E-mail channel, radix-64 ASCII armor is applied (see the ARMOR parameter).  Even if PGP didn't compress the message, the ASCII armor would still render the message unreadable to human eyes.  The recipient must use PGP to strip the armor off and decompress it before reading the message.

If the original plaintext message is in text (not binary) form, there is a way to send a signed message through an E-mail channel in such a way that the signed message is not compressed and the ASCII armor is applied only to the binary signature certificate, but not to the plaintext message.  The CLEARSIG flag provides this useful feature, making it possible to generate a signed message that can be read with human eyes, without the aid of PGP.  Of course, you still need PGP to actually check the signature.

The CLEARSIG flag is preset to "on" beginning with PGP version 2.5.  To enable the full CLEARSIG behavior, the ARMOR and TEXTMODE flags must also be turned on.  Set ARMOR=ON (or use the -a option), and set TEXTMODE=ON (or use the -t option).  If your config file has CLEARSIG turned off, you can turn it back on again directly on the command line, like so:

     pgp -sta +clearsig=on message.txt

This message representation is analogous to the MIC-CLEAR message type used in Internet Privacy Enhanced Mail (PEM).  It is important to note that since this method only applies ASCII armor to the binary signature certificate, and not to the message text itself, there is some risk that the armored message may suffer some accidental molestation while en route.  This can happen if it passes through some E-mail gateway that performs character set conversions, or in some cases extra spaces may be added to or stripped from the ends of lines.  If this occurs, the signature will fail to verify, which may give a false indication of intentional tampering.  But since PEM lives under a similar vulnerability, it seems worth having this feature despite the risks.

Beginning with PGP version 2.2, trailing blanks are ignored on each line in calculating the signature for text in CLEARSIG mode.


Verbose Messages In DOS

VERBOSE - Quiet, Normal, or Verbose Messages

--------------------------------------------

Default setting:  VERBOSE = 1

VERBOSE may be set to 0, 1, or 2, depending on how much detail you want to see from PGP diagnostic messages.  The settings are:

0 - Display messages only if there is a problem.  Unix fans wanted this "quiet mode" setting.

1 - Normal default setting.  Displays a reasonable amount of detail in diagnostic or advisory   messages.

2 - Displays maximum information, usually to help diagnose problems in PGP.  Not recommended for normal use.  Besides, PGP doesn't have any problems, right?


Ask For Confirmation For Key Adds

INTERACTIVE - Ask for Confirmation for Key Adds

-----------------------------------------------

Default Setting:  INTERACTIVE = off

Enabling this mode will mean that if you add a key file containing multiple keys to your key ring, PGP will ask for confirmation for each key before adding it to your key ring.


Generating Keys Without The Manual

NOMANUAL - Let PGP Generate Keys Without the Manual

---------------------------------------------------

Default Setting:  NOMANUAL = off

It is important that the freeware version of PGP not be distributed without the user documentation, which normally comes with it in the standard release package.  This manual contains important information for using PGP, as well as important legal notices.  But some people

have distributed previous versions of PGP without the manual, causing a lot of problems for a lot of people who get it.  To discourage the distribution of PGP without the required documentation, PGP has been changed to require the PGP User's Guide to be found somewhere on your computer (like in your PGP directory) before PGP will let you generate a key pair.  However, some users like to use PGP on tiny palmtop computers with limited storage capacity, so they like to run PGP without the documentation present on their systems.  To satisfy these users, PGP can be made to relax its requirement that the manual be present, by enabling the NOMANUAL flag on the command line during key generation, like so:

    pgp -kg +nomanual

The NOMANUAL flag can only be set on the command line, not in the config file.  Since you must read this manual to learn how to enable this simple override feature, I hope this will still be effective in discouraging the distribution of PGP without the manual.

Some people may object to PGP insisting on finding the manual somewhere in the neighborhood to generate a key.  They bristle against this seemingly authoritarian attitude.  Some people have even modified PGP to defeat this feature, and redistributed their hot wired version to others.  That creates problems for me.  Before I added this feature, there were maimed versions of the PGP distribution package floating around that lacked the manual.  One of them was uploaded to CompuServe, and was distributed to countless users who called me on the phone to ask me why such a complicated program had no manual.  It spread out to BBS systems around the country.  And a

freeware distributor got hold of the package from CompuServe and enshrined it on CD-ROM, distributing thousands of copies without the manual.  What a mess.


Random Numbers

--------------

PGP uses a cryptographically strong pseudorandom number generator for creating temporary conventional session keys.  The seed file for this is called  "randseed.bin".  It too can be kept in whatever directory is indicated by the PGPPATH environmental variable.  If this random

seed file does not exist, it is automatically created and seeded with truly random numbers derived from timing your keystroke latencies.

This generator reseeds the disk file each time it is used by mixing in new key material partially derived with the time of day and other truly random sources.  It uses the conventional encryption algorithm as an engine for the random number generator.  The seed file contains

both random seed material and random key material to key the conventional encryption engine for the random generator.

This random seed file should be at least slightly protected from disclosure, to reduce the risk of an attacker deriving your next or previous session keys.  The attacker would have a very hard time getting anything useful from capturing this random seed file, because the file is cryptographically laundered before and after each use. Nonetheless, it seems prudent to at least try to keep it from falling into the wrong hands.

If you feel uneasy about trusting any algorithmically derived random number source however strong, keep in mind that you already trust the strength of the same conventional cipher to protect your messages. If it's strong enough for that, then it should be strong enough to

use as a source of random numbers for temporary session keys.  Note that PGP still uses truly random numbers from physical sources (mainly keyboard timings) to generate long-term public/secret key pairs.


Conventional Encryption Algorithm

PGP's Conventional Encryption Algorithm

---------------------------------------

As described earlier, PGP "bootstraps" into a conventional single-key encryption algorithm by using a public key algorithm to encipher the conventional session key and then switching to fast conventional cryptography.  So let's talk about this conventional encryption algorithm.  It isn't the DES.

The Federal Data Encryption Standard (DES) used to be a good algorithm for most commercial applications.  But the Government never did trust the DES to protect its own classified data, because the DES key length is only 56 bits, short enough for a brute force attack. Also, the full 16-round DES has been attacked with some success by Biham and Shamir using differential cryptanalysis, and by Matsui using linear cryptanalysis.

The most devastating practical attack on the DES was described at the Crypto '93 conference, where Michael Wiener of Bell Northern Research presented a paper on how to crack the DES with a special machine.  He has fully designed and tested a chip that guesses 50 million DES keys per second until it finds the right one.  Although he has refrained from building the real chips so far, he can get these chips manufactured for $10.50 each, and can build 57000 of them into a special machine for $1 million that can try every DES key in 7 hours, averaging a solution in 3.5 hours.  $1 million can be hidden in the budget of many companies.  For $10 million, it takes 21 minutes to crack, and for $100 million, just two minutes.  With any major government's budget for examining DES traffic, it can be cracked in seconds.  This means that straight 56-bit DES is now effectively dead for purposes of serious data security applications.

A possible successor to DES may be a variation known as "triple DES", which uses two DES keys to encrypt three times, achieving an effective key space of 112 bits.  But this approach is three times slower than normal DES.  A future version of PGP may support triple DES as an option.

PGP does not use the DES as its conventional single-key algorithm to encrypt messages.  Instead, PGP uses a different conventional single-key block encryption algorithm, called DEA(tm).

For the cryptographically curious, the IDEA cipher has a 64-bit block size for the plaintext and the ciphertext.  It uses a key size of 128 bits.  It is based on the design concept of "mixing operations from different algebraic groups".  It runs much faster in software than the DES.  Like the DES, it can be used in cipher feedback (CFB) and cipher block chaining (CBC) modes.  PGP uses it in 64-bit CFB mode.

The IPES/IDEA block cipher was developed at ETH in Zurich by James L. Massey and Xuejia Lai, and published in 1990.  This is not a  "home-grown" algorithm.  Its designers have a distinguished reputation in the cryptologic community.  Early published papers on the algorithm called it IPES (Improved Proposed Encryption Standard), but they later changed the name to IDEA (International Data Encryption Algorithm).  So far, IDEA has resisted attack much better

than other ciphers such as FEAL, REDOC-II, LOKI, Snefru and Khafre. And recent evidence suggests that IDEA is more resistant than the DES to Biham & Shamir's highly successful differential cryptanalysis attack.  Biham and Shamir have been examining the IDEA cipher for

weaknesses, without success.  Academic cryptanalyst groups in Belgium, England, and Germany are also attempting to attack it, as well as the military services from several European countries.  As this new cipher continues to attract attack efforts from the most formidable quarters of the cryptanalytic world, confidence in IDEA is growing with the passage of time.

Every once in a while, I get a letter from someone who has just learned the awful truth that PGP does not use pure RSA to encrypt bulk data.  They are concerned that the whole package is weakened if we use a hybrid public-key and conventional scheme just to speed

things up.  After all, a chain is only as strong as its weakest link.  They demand an explanation for this apparent "compromise" in the strength of PGP.  This may be because they have been caught up in the public's reverence and awe for the strength and mystique of RSA, mistakenly believing that RSA is intrinsically stronger than any conventional cipher.  Well, it's not.

People who work in factoring research say that the workload to exhaust all the possible 128-bit keys in the IDEA cipher would roughly equal the factoring workload to crack a 3100-bit RSA key, which is quite a bit bigger than the 1024-bit RSA key size that most people use for high security applications.  Given this range of key sizes, and assuming there are no hidden weaknesses in the conventional cipher, the weak link in this hybrid approach is in the

public key algorithm, not the conventional cipher.

It is not ergonomically practical to use pure RSA with large keys to encrypt and decrypt long messages.  A 1024-bit RSA key would decrypt messages about 4000 times slower than the IDEA cipher.  Absolutely no one does it that way in the real world.  Many people less experienced

in cryptography do not realize that the attraction of public key cryptography is not because it is intrinsically stronger than a conventional cipher-- its appeal is because it helps you manage keys

more conveniently.

Not only is RSA too slow to use on bulk data, but it even has certain weaknesses that can be exploited in some special cases of particular kinds of messages that are fed to the RSA cipher, even for large keys.  These special cases can be avoided by using the hybrid approach of using RSA to encrypt random session keys for a conventional cipher, like PGP does.  So the bottom line is this:  Using pure RSA on bulk data is the wrong approach, period.  It's too slow, it's not stronger, and may even be weaker.  If you find a software application that uses pure RSA on bulk data, it probably means the implementor does not understand these issues, which could imply he doesn't understand other important concepts of cryptography.


Data Compresion

Data Compression

----------------

PGP normally compresses the plaintext before encrypting it. It's too late to compress it after it has been encrypted; encrypted data is incompressible.  Data compression saves modem transmission time and disk space and more importantly strengthens cryptographic security.

Most cryptanalysis techniques exploit redundancies found in the plaintext to crack the cipher.  Data compression reduces this redundancy in the plaintext, thereby greatly enhancing resistance to cryptanalysis.  It takes extra time to compress the plaintext, but from a security point of view it seems worth it, at least in my cautious opinion.

Files that are too short to compress or just don't compress well are not compressed by PGP.

If you prefer, you can use PKZIP to compress the plaintext before encrypting it.  PKZIP is a widely-available and effective MSDOS shareware compression utility from PKWare, Inc.  Or you can use ZIP, a PKZIP-compatible freeware compression utility on Unix and other systems, available from Jean-Loup Gailly.  There is some advantage in using PKZIP or ZIP in certain cases, because unlike PGP's built-in compression algorithm, PKZIP and ZIP have the nice feature of compressing multiple files into a single compressed file, which is reconstituted again into separate files when decompressed.  PGP will not try to compress a plaintext file that has already been compressed.  After decrypting, the recipient can decompress the plaintext with PKUNZIP.  If the decrypted plaintext is a PKZIP compressed file, PGP automatically recognizes this and advises the recipient that the decrypted plaintext appears to be a PKZIP file.

For the technically curious readers, the current version of PGP uses the freeware ZIP compression routines written by Jean-loup Gailly, Mark Adler, and Richard B. Wales.  This ZIP software uses functionally-equivalent compression algorithms as those used by PKWare's new PKZIP 2.0.  This ZIP compression software was selected for PGP mainly because of its free portable C source code availability, and because it has a really good compression ratio, and

because it's fast.

Peter Gutmann has also written a nice compression utility called HPACK, available for free from many Internet FTP sites.  It encrypts the compressed archives, using PGP data formats and key rings.  He wanted me to mention that here.


Message Digests and Digital Signatures

--------------------------------------

To create a digital signature, PGP encrypts with your secret key. But PGP doesn't actually encrypt your entire message with your secret key-- that would take too long.  Instead, PGP encrypts a "message digest".

The message digest is a compact (128 bit) "distillate" of your message, similar in concept to a checksum.  You can also think of it as a "fingerprint" of the message.  The message digest "represents" your message, such that if the message were altered in any way, a different Message digest would be computed from it.  This makes it possible to detect any changes made to the message by a forger.  A message digest is computed using a cryptographically strong one-way hash function of the message.  It would be computationally infeasible for an attacker to devise a substitute message that would produce an identical message digest.  In that respect, a message digest is much better than a checksum, because it is easy to devise a different

message that would produce the same checksum.  But like a checksum, you can't derive the original message from its message digest.

A message digest alone is not enough to authenticate a message.  The message digest algorithm is publicly known, and does not require knowledge of any secret keys to calculate.  If all we did was attach a message digest to a message, then a forger could alter a message and simply attach a new message digest calculated from the new altered message.  To provide real authentication, the sender has to encrypt (sign) the message digest with his secret key.

A message digest is calculated from the message by the sender.  The sender's secret key is used to encrypt the message digest and an electronic timestamp, forming a digital signature, or signature certificate.  The sender sends the digital signature along with the message.  The receiver receives the message and the digital signature, and recovers the original message digest from the digital signature by decrypting it with the sender's public key.  The receiver computes a new message digest from the message, and checks to see if it matches the one recovered from the digital signature.  If it matches, then that proves the message was not altered, and it came from the sender who owns the public key used to check the signature.

A potential forger would have to either produce an altered message that produces an identical message digest (which is infeasible), or he would have to create a new digital signature from a different message digest (also infeasible, without knowing the true sender's secret key).

Digital signatures prove who sent the message, and that the message was not altered either by error or design.  It also provides non-repudiation, which means the sender cannot easily disavow his signature on the message.

Using message digests to form digital signatures has other advantages besides being faster than directly signing the entire actual message with the secret key.  Using message digests allows signatures to be of a standard small fixed size, regardless of the size of the actual message.  It also allows the software to check the message integrity automatically, in a manner similar to using checksums.  And it allows signatures to be stored separately from messages, perhaps even in a public archive, without revealing sensitive information about the actual messages, because no one can derive any message content from a message digest.

The message digest algorithm used here is the MD5 Message Digest Algorithm, placed in the public domain by RSA Data Security, Inc. MD5's designer, Ronald Rivest, writes this about MD5:

"It is conjectured that the difficulty of coming up with two messages having the same message digest is on the order of 2^64 operations, and that the difficulty of coming up with any message having a given message digest is on the order of 2^128 operations.  The MD5 algorithm has been carefully scrutinized for weaknesses.  It is, however, a relatively new algorithm and further security analysis is of course justified, as is the case with any new proposal of this sort.  The level of security provided by MD5 should be sufficient for implementing very high security hybrid digital signature schemes based on MD5 and the RSA public-key cryptosystem."


Compatibility's With Previous Versions Of PGP

Compatibility with Previous and Future Versions of PGP

==============================================

PGP version 2.6 can read anything produced by versions 2.3 through 2.7.  However, because of a negotiated agreement between MIT and RSA Data Security, PGP 2.6 was programmed to change its behavior slightly on 1 September 1994, triggered by a built-in software timer.  On that date, version 2.6 started producing a new and slightly different data format for messages, signatures and keys.  PGP 2.6 will still be able to read and process messages, signatures, and keys produced under the old format, but it will generate the new format.  This change is intended to discourage people from continuing to use the older (2.3a and earlier) versions of PGP, which Public Key Partners contends infringes its RSA patent (see the section on Legal Issues).  ViaCrypt PGP (see the section Where to Get a Commercial Version of PGP),

versions 2.4 and 2.7, avoids questions of infringement through Viacrypt's license arrangement with Public Key Partners.  PGP 2.5 and 2.6 avoid questions of infringement by using the RSAREF(TM) Cryptographic Toolkit, under license from RSA Data Security, Inc.

Outside the United States, the RSA patent is not in force, so PGP users there are free to use implementations of PGP that do not rely on RSAREF and its restrictions.  See the notes on foreign versions in the Legal Issues section later in this manual.  It seems likely that any versions of PGP prepared outside the US will accept the new format, whose detailed description is available from MIT.  If everyone upgrades before September 1994, or soon thereafter, there will be little interoperability problems.

This format change beginning with 2.6 is similar to the process that naturally happens when new features are added, causing older versions of PGP to be unable to read stuff from the newer PGP, while the newer version can still read the old stuff.  The only difference is that this is a "legal upgrade", instead of a technical one.  It's a worthwhile change, if it can achieve peace in our time.

According to ViaCrypt, which sells a commercial version of PGP, ViaCrypt PGP will evolve to maintain interoperability with new freeware versions of PGP.

There is a another change that effects interoperability with earlier versions of PGP.  Unfortunately, due to data format limitations imposed by RSAREF, PGP 2.5 and 2.6 cannot interpret any messages or signatures made with PGP version 2.2 or earlier.  Since we had no

choice but to use the new data formats, because of the need to switch to RSAREF, we can't do anything about this problem.

Beginning with version 2.4 (which was ViaCrypt's first version) through at least 2.6, PGP does not allow you to generate RSA keys bigger than 1024 bits.  The upper limit was always intended to be 1024 bits -- there had to be some kind of upper limit, for performance and interoperability reasons.  But because of a bug in earlier versions of PGP, it was possible to generate keys larger than 1024 bits.  These larger keys caused interoperability problems

between different older versions of PGP that used different arithmetic algorithms with different native word sizes.  On some platforms, PGP choked on the larger keys.  In addition to these older

key size problems, the 1024-bit limit is now enforced by RSAREF.  A 1024-bit key is very likely to be well out of reach of attacks by major governments.  In a future version, PGP will support bigger keys.

In general, there is compatibility from version 2.0 upwards through 2.4.  Because new features are added, older versions may not always be able to handle some files created with newer versions.  Because of massive changes to all the algorithms and data structures, PGP version 2.0 (and later) is not even slightly compatible with PGP version 1.0, which no one uses anymore anyway.

Future versions of PGP may have to change the data formats for messages, signatures, keys and key rings, in order to provide important new features.  We will endeavor to make future versions handle keys, signatures, and messages from this version, but this is not guaranteed.  Future releases may provide conversion utilities to convert old keys, but you may have to dispose of old messages created with the old PGP.  Also, this current version may not be able to read

stuff produced from all future versions.


Vulnerabilities Overview
Vulnerabilities

===============

No data security system is impenetrable.  PGP can be circumvented in a variety of ways.  In any data security system, you have to ask yourself if the information you are trying to protect is more valuable to your attacker than the cost of the attack.  This should lead you to protecting yourself from the cheapest attacks, while not worrying about the more expensive attacks.

Some of the discussion that follows may seem unduly paranoid, but such an attitude is appropriate for a reasonable discussion of vulnerability issues.


Compromised Pass Phrase and Secret Key

--------------------------------------

Probably the simplest attack is if you leave your pass phrase for your secret key written down somewhere.  If someone gets it and also gets your secret key file, they can read your messages and make signatures in your name.

Don't use obvious passwords that can be easily guessed, such as the names of your kids or spouse.  If you make your pass phrase a single word, it can be easily guessed by having a computer try all the words in the dictionary until it finds your password.  That's why a pass phrase is so much better than a password.  A more sophisticated attacker may have his computer scan a book of famous quotations to find your pass phrase.  An easy to remember but hard to guess pass phrase can be easily constructed by some creatively nonsensical sayings or very obscure literary quotes.

For further details, see the section "How to Protect Secret Keys from

Disclosure" in the Essential Topics volume of the PGP User's Guide.


Public Key Tampering

--------------------

A major vulnerability exists if public keys are tampered with.  This may be the most crucially important vulnerability of a public key cryptosystem, in part because most novices don't immediately recognize it.  The importance of this vulnerability, and appropriate hygienic countermeasures, are detailed in the section "How to Protect Public Keys from Tampering" in the Essential Topics volume.

To summarize:  When you use someone's public key, make certain it has not been tampered with.  A new public key from someone else should be trusted only if you got it directly from its owner, or if it has been signed by someone you trust.  Make sure no one else can tamper with your own public key ring.  Maintain physical control of both your public key ring and your secret key ring, preferably on your own personal computer rather than on a remote timesharing system.  Keep a backup copy of both key rings.


Note Quite Deleted Files

"Not Quite Deleted" Files

-------------------------

Another potential security problem is caused by how most operating systems delete files.  When you encrypt a file and then delete the original plaintext file, the operating system doesn't actually physically erase the data.  It merely marks those disk blocks as deleted, allowing the space to be reused later.  It's sort of like discarding sensitive paper documents in the paper recycling bin instead of the paper shredder.  The disk blocks still contain the original sensitive data you wanted to erase, and will probably eventually be overwritten by new data at some point in the future. If an attacker reads these deleted disk blocks soon after they have been deallocated, he could recover your plaintext.

In fact this could even happen accidentally, if for some reason something went wrong with the disk and some files were accidentally deleted or corrupted.  A disk recovery program may be run to recover the damaged files, but this often means some previously deleted files are resurrected along with everything else.  Your confidential files that you thought were gone forever could then reappear and be inspected by whomever is attempting to recover your damaged disk.

Even while you are creating the original message with a word processor or text editor, the editor may be creating multiple temporary copies of your text on the disk, just because of its internal workings.  These temporary copies of your text are deleted by the word processor when it's done, but these sensitive fragments are still on your disk somewhere.

Let me tell you a true horror story.  I had a friend, married with young children, who once had a brief and not very serious affair.  She wrote a letter to her lover on her word processor, and deleted the letter after she sent it.  Later, after the affair was over, the floppy disk got damaged somehow and she had to recover it because it contained other important documents.  She asked her husband to salvage the disk, which seemed perfectly safe because she knew she had deleted the incriminating letter.  Her husband ran a commercial disk recovery software package to  salvage the files.  It recovered the files all right, including the deleted letter.  He read it, which set off a tragic chain of events.

The only way to prevent the plaintext from reappearing is to somehow cause the deleted plaintext files to be overwritten.  Unless you know for sure that all the deleted disk blocks will soon be reused, you must take positive steps to overwrite the plaintext file, and also any fragments of it on the disk left by your word processor.  You can overwrite the original plaintext file after  encryption by using the PGP -w (wipe) option.  You can take care of any fragments of the

plaintext left on the disk by using any of the disk utilities available that can overwrite all of the unused blocks on a disk.  For example, the Norton Utilities for MSDOS can do this.

Even if you overwrite the plaintext data on the disk, it may still be possible for a resourceful and determined attacker to recover the data.  Faint magnetic traces of the original data remain on the disk after it has been overwritten.  Special sophisticated disk recovery

hardware can sometimes be used to recover the data.


Viruses and Trojan Horses

-------------------------

Another attack could involve a specially-tailored hostile computer virus or worm that might infect PGP or your operating system.  This hypothetical virus could be designed to capture your pass phrase or secret key or deciphered messages, and covertly write the captured information to a file or send it through a network to the virus's owner.  Or it might alter PGP's behavior so that signatures are not properly checked.  This attack is cheaper than cryptanalytic attacks.

Defending against this falls under the category of defending against viral infection generally.  There are some moderately capable anti-viral products commercially available, and there are hygienic procedures to follow that can greatly reduce the chances of viral infection.  A complete treatment of anti-viral and anti-worm countermeasures is beyond the scope of this document.  PGP has no defenses against viruses, and assumes your own personal computer is a

trustworthy execution environment.  If such a virus or worm actually appeared, hopefully word would soon get around warning everyone.

Another similar attack involves someone creating a clever imitation of PGP that behaves like PGP in most respects, but doesn't work the way it's supposed to.  For example, it might be deliberately crippled to not check signatures properly, allowing bogus key certificates to be accepted.  This "Trojan horse" version of PGP is not hard for an attacker to create, because PGP source code is widely available, so anyone could modify the source code and produce a lobotomized zombie imitation PGP that looks real but does the bidding of its diabolical master.  This Trojan horse version of PGP could then be widely circulated, claiming to be from me.  How insidious.

You should make an effort to get your copy of PGP from a reliable source, whatever that means.  Or perhaps from more than one independent source, and compare them with a file comparison utility.

There are other ways to check PGP for tampering, using digital signatures.  If someone you trust signs the executable version of PGP, vouching for the fact that it has not been infected or tampered with, you can be reasonably sure that you have a good copy.  You could use an earlier trusted version of PGP to check the signature on a later suspect version of PGP.  But this will not help at all if your operating system is infected, nor will it detect if your original copy of PGP.EXE has been maliciously altered in such a way as to compromise its own ability to check signatures.  This test also assumes that you have a good trusted copy of the public key that you

use to check the signature on the PGP executable.

I recommend you not trust your copy of PGP unless it was originally distributed by MIT or ViaCrypt, or unless it comes with a digitally signed endorsement from me.  Every new version comes with one or more digital signatures in the distribution package, signed by the originator of that release package.  This is usually someone representing MIT or ViaCrypt, or whoever  released that version. Check the signatures on the version that you get.  I have actually seen several bogus versions of PGP distribution packages, even from apparently reliable freeware distribution channels such as CD-ROM distributors and Compuserve.  Always check the signature when you get a new version.


Physical Security Breach

------------------------

A physical security breach may allow someone to physically acquire your plaintext files or printed messages.  A determined opponent might accomplish this through burglary, trash-picking, unreasonable search and seizure, or bribery, blackmail or infiltration of your staff.  Some of these attacks may be especially feasible against grassroots political organizations that depend on a largely volunteer staff.  It has been widely reported in the press that the FBI's COINTELPRO program used burglary, infiltration, and illegal bugging against antiwar and civil rights groups.  And look what happened at the Watergate Hotel.

Don't be lulled into a false sense of security just because you have a cryptographic tool.  Cryptographic techniques protect data only while it's encrypted-- direct physical security violations can still compromise plaintext data or written or spoken information.

This kind of attack is cheaper than cryptanalytic attacks on PGP.


Tempest Attacks

---------------

Another kind of attack that has been used by well-equipped opponents involves the remote detection of the electromagnetic signals from your computer.  This expensive and somewhat labor-intensive attack is probably still cheaper than direct cryptanalytic attacks.  An

appropriately instrumented van can park near your office and remotely pick up all of your keystrokes and messages displayed on your computer video screen.  This would compromise all of your passwords, messages, etc.  This attack can be thwarted by properly shielding all of your computer equipment and network cabling so that it does not emit these signals.  This shielding technology is known as "Tempest", and is used by some Government agencies and defense contractors.  There are hardware vendors who supply Tempest shielding commercially, although it may be subject to some kind of Government licensing.  Now why do you suppose the  government would restrict access to Tempest shielding?


Exposure On Muli-User Systems

Exposure on Multi-user Systems

------------------------------

PGP was originally designed for a single-user MSDOS machine under your direct physical control.  I run PGP at home on my own PC, and unless someone breaks into my house or monitors my electromagnetic emissions, they probably can't see my plaintext files or secret keys.

But now PGP also runs on multi-user systems such as Unix and VAX/VMS. On multi-user systems, there are much greater risks of your plaintext or keys or passwords being exposed.  The Unix system administrator or a clever intruder can read your plaintext files, or perhaps even use

special software to covertly monitor your keystrokes or read what's on your screen.  On a Unix system, any other user can read your environment information remotely by simply using the Unix "ps" command.  Similar problems exist for MSDOS machines connected on a local area network.  The actual security risk is dependent on your particular situation.  Some multi-user systems may be safe because all the users are trusted, or because they have system security measures that are safe enough to withstand the attacks available to the intruders, or because there just aren't any sufficiently interested intruders.  Some Unix systems are safe because they are only used by one user-- there are even some notebook computers running Unix.  It would be unreasonable to simply exclude PGP from running on all Unix systems.

PGP is not designed to protect your data while it is in plaintext form on a compromised system.  Nor can it prevent an intruder from using sophisticated measures to read your secret key while it is being used.  You will just have to recognize these risks on multi-user systems, and adjust your expectations and behavior accordingly.  Perhaps your situation is such that you should consider running PGP only on an isolated single-user system under your direct physical control.  That's what I do, and that's what I recommend.


Traffic Analysis

----------------

Even if the attacker cannot read the contents of your encrypted messages, he may be able to infer at least some useful information by observing where the messages come from and where they are going, the size of the messages, and the time of day the messages are sent. This is analogous to the attacker looking at your long distance phone bill to see who you called and when and for how long, even though the actual content of your calls is unknown to the attacker.  This is called traffic analysis.  PGP alone does not protect against traffic analysis.  Solving this problem would require specialized communication protocols designed to reduce exposure to traffic analysis in your communication environment, possibly with some cryptographic assistance.


Protecting Against Bogus Time Stamps

-----------------------------------

A somewhat obscure vulnerability of PGP involves dishonest users creating bogus timestamps on their own public key certificates and signatures.  You can skip over this section if you are a casual user and aren't deeply into obscure public key protocols.

There's nothing to stop a dishonest user from altering the date and time setting of his own system's clock, and generating his own public key certificates and signatures that appear to have been created at a different time.  He can make it appear that he signed something earlier or later than he actually did, or that his public/secret key pair was created earlier or later.  This may have some legal or financial benefit to him, for example by creating some kind of loophole that might allow him to repudiate a signature.

I think this problem of falsified time stamps in digital signatures is no worse than it is already in handwritten signatures.  Anyone may write a date next to their handwritten signature on a contract with any date they choose, yet no one seems to be alarmed over this state of affairs.  In some cases, an "incorrect" date on a handwritten signature might not be associated with actual fraud.  The time stamp might be when the signator asserts that he signed a document, or maybe when he wants the signature to go into effect.

In situations where it is critical that a signature be trusted to have the actual correct date, people can simply use notaries to witness and date a handwritten signature.  The analog to this in

digital signatures is to get a trusted third party to sign a signature certificate, applying a trusted time stamp.  No exotic or overly formal protocols are needed for this.  Witnessed signatures have long been recognized as a legitimate way of determining when a document was signed.

A trustworthy Certifying Authority or notary could create notarized signatures with a trustworthy time stamp.  This would not necessarily require a centralized authority.  Perhaps any trusted introducer or disinterested party could serve this function, the same way real notary publics do now.  When a notary signs other people's signatures, it creates a signature certificate of a signature certificate.  This would serve as a witness to the signature the same way real notaries now witness handwritten signatures.  The notary could enter the detached signature certificate (without the actual whole document that was signed) into a special log controlled by the

notary.  Anyone can read this log.  The notary's signature would have a trusted time stamp, which might have greater credibility or more legal significance than the time stamp in the original signature.

There is a good treatment of this topic in Denning's 1983 article in IEEE Computer (see references).  Future enhancements to PGP might have features to easily manage notarized signatures of signatures, with trusted time stamps.


Cryptanalysis

-------------

An expensive and formidable cryptanalytic attack could possibly be mounted by someone with vast supercomputer resources, such as a Government intelligence agency.  They might crack your RSA key by using some new secret factoring breakthrough.  Perhaps so, but it is noteworthy that the US Government trusts the RSA algorithm enough in some cases to use it to protect its own nuclear weapons, according to Ron Rivest.  And civilian academia has been intensively attacking it without success since 1978.

Perhaps the Government has some classified methods of cracking the IDEA(tm) conventional encryption algorithm used in PGP.  This is every cryptographer's worst nightmare.  There can be no absolute security guarantees in practical cryptographic implementations.

Still, some optimism seems justified.  The IDEA algorithm's designers are among the best cryptographers in Europe.  It has had extensive security analysis and peer review from some of the best cryptanalysts in the unclassified world.  It appears to have some design advantages

over the DES in withstanding differential and linear cryptanalysis, which have both been used to crack the DES.

Besides, even if this algorithm has some subtle unknown weaknesses, PGP compresses the plaintext before encryption, which should greatly reduce those weaknesses.  The computational workload to crack it is likely to be much more expensive than the value of the message.

If your situation justifies worrying about very formidable attacks of this caliber, then perhaps you should contact a data security consultant for some customized data security approaches tailored to your special needs.  Boulder Software Engineering, whose address and

phone are given at the end of this document, can provide such services.

In summary, without good cryptographic protection of your data communications, it may have been practically effortless and perhaps even routine for an opponent to intercept your messages, especially those sent through a modem or E-mail system.  If you use PGP and follow reasonable precautions, the attacker will have to expend far more effort and expense to violate your privacy.

If you protect yourself against the simplest attacks, and you feel confident that your privacy is not going to be violated by a determined and highly resourceful attacker, then you'll probably be safe using PGP.  PGP gives you Pretty Good Privacy.


Legal Issues

============

Trademarks, Copyrights, and Warranties

--------------------------------------

"PGP", "Pretty Good Privacy", "Phil's Pretty Good Software", and the "Pretty Good" label for computer software and hardware products are all trademarks of Philip R. Zimmermann.

PGP is (c) Copyright Philip R. Zimmermann, 1990-1994.  All rights reserved.  The PGP User's Guide is also copyright Philip Zimmermann, 1990-1994.  All rights reserved.  These rights include but are not limited to any foreign language translations of the manual or the software, and all derivative works of both.

MIT may have a copyright on the particular software distribution package that they distribute from the MIT FTP site.  This copyright on the "compilation" of the distribution package in no way implies that MIT has a copyright on PGP itself, or its user documentation.

The author assumes no liability for damages resulting from the use of this software, even if the damage results from defects in this software, and makes no representations concerning the merchantability of this software or its suitability for any specific purpose.  It is provided "as is" without express or implied warranty of any kind. Because certain actions may delete files or render them unrecoverable, the author assumes no responsibility for the loss or modification of any data.


Patent Rights on the Algorithms

-------------------------------

The RSA public key cryptosystem was developed at MIT, which holds a patent on it (U.S. patent #4,405,829, issued 20 Sep 1983).  A company in California called Public Key Partners (PKP) holds the exclusive commercial license to sell and sub-license the RSA public key

cryptosystem.  MIT distributes a freeware version of PGP under the terms of the RSAREF license from RSA Data Security, Inc. (RSADSI).

At the time of this writing (September 1994), it appears that PKP may be breaking up soon, in which case the patents they hold may fall into other hands.  The RSA patent may end up with RSADSI.

Non-US users of earlier versions of PGP should note that the RSA patent does not apply outside the US, and at least at the time of this writing, the author is not aware of any RSA patent in any other country.  Federal agencies may use the RSA algorithm, because the Government paid for the development of RSA with grants from the National Science Foundation and the Navy.  But despite the fact of Government users having free access to the RSA algorithm, Government

use of PGP has additional restrictions imposed by the agreement I have with ViaCrypt, as explained later.

I wrote my PGP software from scratch, with my own independently developed implementation of the RSA algorithm.  Before publishing PGP in 1991, I got a formal written legal opinion from a patent attorney with extensive experience in software patents.  I'm convinced that

publishing PGP the way I did does not violate patent law.

Not only did PKP acquire the exclusive patent rights for the RSA cryptosystem, but they also acquired the exclusive rights to three other patents covering other public key schemes invented by others at Stanford University, also developed with federal funding.  This one company claims to have a legal lock in the USA on nearly all practical public key cryptosystems.  They even appear to be claiming patent rights on the very concept of public key cryptography, regardless of what clever new original algorithms are independently invented by others.  I find such a comprehensive monopoly troubling, because I think public key cryptography is destined to become a crucial technology in the protection of our civil liberties and privacy in our increasingly connected society.  At the very least, it places these vital tools at risk by affording to the  government a single pressure point of influence.

Beginning with PGP version 2.5 (distributed by MIT, the holders of the original RSA patent), the freeware version of PGP uses the RSAREF subroutine library to perform its RSA calculations, under the RSAREF license, which allows noncommercial use in the USA.  RSAREF is a subroutine package from RSA Data Security Inc, that implements the RSA algorithm.  The RSAREF subroutines are used instead of PGP's original subroutines to implement the RSA functions in PGP.  See the RSAREF license for terms and conditions of use of RSAREF applications.

PGP 2.5 was released by MIT for a brief test period in May, 1994 before releasing 2.6.  PGP 2.5 was released under the 16 March, 1994 RSAREF license, which is a perpetual license, so it may legally be used forever in the US.  But it would be better for PGP's legal and political future for users in the United States to upgrade to version 2.6 or later to facilitate the demise of PGP 2.3a and earlier versions.  Also, PGP 2.5 has bugs that are corrected in 2.6, and 2.5 will not read the new data format after September 1, 1994.  (See the section on Compatibility with Previous and Future Versions of PGP.)

The PGP 2.0 release was a joint effort of an international team of software engineers, implementing enhancements to the original PGP with design guidance from me.  It was released by Branko Lankester in The Netherlands and Peter Gutmann in New Zealand, out of reach of US

patent law.  Although released only in Europe and New Zealand, it spontaneously spread to the USA without help from me or the PGP development team.

The IDEA(tm) conventional block cipher used by PGP is covered by a patent in Europe, held by ETH and a Swiss company called Ascom-Tech AG.  The US Patent number is 5,214,703, and the European patent number is EP 0 482 154 B1.  IDEA(tm) is a trademark of Ascom-Tech AG. There is no license fee required for noncommercial use of IDEA. Commercial users of IDEA may obtain licensing details from Dieter Profos, Ascom Tech AG, Teleservices Section, Postfach 151, 4502 Solothurn, Switzerland, Tel +41 65 242885, Fax +41 65 235761.

Ascom-Tech AG has granted permission for the freeware version PGP to use the IDEA cipher in non-commercial uses, everywhere.  In the US and Canada, all commercial or government users must obtain a licensed version from ViaCrypt, who has a license from Ascom-Tech for the IDEA cipher.

Ascom-Tech has recently been changing its policies regarding the use of IDEA in PGP for commercial use outside the US, and that policy still seems to be in flux.  They tell me that their current thinking is as follows:  They will allow commercial users of PGP outside the US or Canada to use IDEA in PGP without paying royalties to Ascom-Tech, because it is not currently possible for commercial users to buy a licensed version of PGP outside the US or Canada.  If the legal situation in the USA changes in the future, so that users outside the US or Canada can buy a licensed version of PGP (either from ViaCrypt, or from me, or from a foreign enterprise licensed by me), then Ascom-Tech will begin enforcing its patent licensing policies on commercial users who are in a position to buy a licensed version of PGP.  To get a more up-to-date report on this, contact Ascom-Tech AG.

The ZIP compression routines in PGP come from freeware source code, with the author's permission.  I'm not aware of any patents on the compression algorithms used in the ZIP routines.


Freeware Status and Restrictions

--------------------------------

PGP is not shareware, it's freeware.  Published as a community service.  Giving PGP away for free will encourage far more people to use it, which will have a greater social impact.  Feel free to disseminate the complete unmodified PGP release package as widely as possible, but be careful not to violate U.S. export controls if you live in the USA.  Give it to all your friends.  If you have access to any electronic Bulletin Board Systems, please upload the complete PGP

executable object release package to as many BBS's as possible.

You may also disseminate the source code release package.  PGP's source code is published to assist public scrutiny of PGP to show that it has no hidden weaknesses or back doors, and to help people to find bugs and report them.  Recompile it and port it to new target

machines.  Experiment with the code and learn from it.

I place no restraints on your modifying the source code for your own use.  However, do not distribute a modified version of PGP under the name "PGP" without first getting permission from me.  Please respect this restriction.  PGP's reputation for cryptographic integrity depends on maintaining strict quality control on PGP's cryptographic algorithms and protocols.  Beyond that, ad hoc "improvements" to PGP can affect interoperability, which creates user confusion and

compatibility problems that could damage PGP's (and my own) reputation and undermine the good will earned by the PGP trademark.

This has already started to happen, which is why I'm making a point of it here.  This creates technical support headaches, and I get phone calls from confused users who run into problems either because they have a mutant strain of PGP, or are trying to process a key,

signature, or message that came from an incompatible mutant strain of PGP.  The source code to PGP was not published to help spawn these mutant strains.

If you want to distribute a modified version of PGP, or use a modified version to send messages to other people, you should name the program in such a way that no one could mistake it for PGP.  The messages, signatures, and keys it produces must also be labeled in such a way

that no one could mistake them for material produced by PGP.  If you feel you must modify your copy of PGP, and there is any chance that the modified version could escape into the environment, please contact me first to discuss some easy methods for how to prevent people from confusing your version with the standard PGP.  Perhaps we'll even decide that your changes are appropriate for incorporating into the standard PGP release.

Also, you should note that official executable versions of PGP are always released signed by the PGP developers, so you can verify their authenticity.  If you find a corrupted copy of PGP, or notice one being distributed, please contact the people doing the distribution and suggest that they replace this with an authentic version.

Some older versions of PGP were published under the terms of the General Public License (GPL), a license designed by the Free Software Foundation to protect the status of free software.  Newer freeware versions of PGP are no longer published under the GPL. The RSAREF

licensing terms are more stringent than those of the GPL. But even if a version of PGP is published without RSAREF, in a situation or place where the RSA patent does not apply, I still do not want the GPL to apply to PGP, for a variety of reasons, not the least of which is because the GPL is not optimal for protecting PGP from being republished with ad-hoc "improvements".

Outside the United States, the RSA patent is not in force, so PGP users there are free to use implementations of PGP that do not rely on RSAREF and its restrictions.  Canadians may use PGP without using RSAREF, and there are legal ways to export PGP to Canada.  In Canada, where RSAREF is not needed, it is easy to modify and recompile the current PGP source code to perform the RSA calculations without using the RSAREF library, just as it was done in PGP 2.3a.  In such a case, this modified PGP may be re-released under the identical licensing terms as the current official freeware PGP release, but without the RSAREF-specific restrictions.  It may not be re-released under the GPL, as certain older versions were.  And this manual must accompany it.  That modified version of PGP may not be used in environments where RSAREF would be needed.


Restrictions on Commercial Use of PGP

-------------------------------------

The freeware version of PGP is for personal, non-commercial use.  For commercial use in the USA or Canada, contact ViaCrypt in Phoenix, Arizona (phone 602 944-0773, or email viacrypt@acm.org).

I made an agreement with ViaCrypt in the summer of 1993 to license the exclusive commercial rights to PGP, so that there would be a way for corporations to use PGP without risk of a patent infringement lawsuit from PKP.  For PGP to succeed in the long term as a viable industry standard, the legal stigma associated with the RSA patent rights had to be resolved.  ViaCrypt had already obtained a patent license from PKP to make, use, and sell products that practice the RSA patents. ViaCrypt offered a way out of the patent quagmire for PGP to penetrate

the corporate environment.  They could sell a fully-licensed version of PGP, but only if I licensed it to them under these terms.  So we entered into an agreement to do that, opening the door for PGP's future in the commercial sector, which was necessary for PGP's long-term political future.

Therefore, regardless of the complexities and partially overlapping restrictions from all the other terms and conditions imposed by the various patent and copyright licenses (RSA, RSAREF, and IDEA) from various third parties, an additional overriding restriction on PGP usage is imposed by my own agreement with ViaCrypt: The freeware version of PGP is only for personal, non-commercial use -- all other users in the USA and Canada must obtain a fully licensed version of

PGP from ViaCrypt.  The restrictions imposed by my agreement with ViaCrypt do not apply outside the USA or Canada.

Finally, if you want to turn PGP into a commercial product and make money selling it, then we must agree on a way for me to also make money on it.  If you use PGP in such a manner that you must pay patent royalties or any other software licensing fees to the patent holders for any cryptographic algorithms used by PGP, then we must agree on a way for me to also be paid in some manner.  Buying PGP from ViaCrypt is one way to meet this requirement.


Other Licensing Restrictions

----------------------------

Under no circumstances may PGP be distributed without the PGP documentation, including this PGP User's Guide.  And, assuming this is an RSAREF version of PGP, the RSAREF license agreement must be kept with it.  You must also keep the copyright, patent, and trademark notices on PGP and its documentation.

The standard freeware PGP release is primarily distributed in electronic form, as a single compressed archive file, containing a collection of files in a "shrink-wrapped" package.  This package should not be broken up and the components separately distributed -- in the interests of quality control, we want to make it difficult for users to obtain PGP without getting the full release package.


Distribution

------------

In the USA, PGP is available for free from the Massachusetts Institute of Technology, under the restrictions described above.

The primary release site for PGP is the Massachusetts Institute of Technology, at their FTP site "net-dist.mit.edu", in the /pub/PGP directory.  You may obtain free copies or updates to PGP from this site, or any other Internet FTP site or BBS that PGP has spread to. Don't ask me for a copy directly from me, especially if you live outside the US or Canada.  I recommend that you not use any modified version of PGP that comes from any other source, other than MIT,

ViaCrypt, or me, unless it is accompanied by a signed endorsement from me personally.  You can get the official release software from many other distribution sites "downstream" from MIT. Hopefully, all these other sites are adhering to US export controls.

The PGP version 2.6.2 executable object release package for MSDOS contains the PGP executable software, documentation, RSAREF license, sample key rings including my own public key, and signatures for the software and this manual, all in one PKZIP compressed file called pgp262.zip.  The PGP source release package for MSDOS contains all the C source files in one PKZIP compressed file called pgp262s.zip. The filename for the release package is derived from the version number of the release.


Export Controls

---------------

The U.S. Government has made it illegal in most cases to export good cryptographic technology, and that may include PGP.  They regard this kind of software just like they regard munitions.  This is determined not by legislation, but by administrative policies of the State

Department, Defense Department and Commerce Department.

The U.S. Government is using export restrictions as a means of suppressing both domestic and foreign availability of cryptographic technology.  In particular, it is trying to suppress the emergence of an international standard for cryptographic protocols, until it can establish the Escrowed Encryption Standard (the Clipper chip) as the dominant standard.

Any export restrictions on PGP are imposed by the US Government. This does not imply that I or MIT agree with these restrictions.  We just comply with them.  We do not impose additional licensing restrictions of our own on the use of PGP outside of the US, other than those restrictions that already apply inside the US.  PGP may be subject to export controls.  Anyone wishing to export it should first consult the State Department's Office of Defense Trade Controls.

I will not export this software out of the US or Canada in cases when it is illegal to do so under US controls, and I urge other people not to export it on their own.  If you live outside the US or Canada, I urge you not to violate US export laws by getting any version of PGP in a way that violates those laws.  Since thousands of domestic users got the first version after its initial publication, it somehow leaked out of the US and spread itself widely abroad, like dandelion seeds blowing in the wind.

Starting with PGP version 2.0 through version 2.3a, the release point of the software has been outside the US, on publicly-accessible computers in Europe.  Each release was electronically sent back into the US and posted on publicly-accessible computers in the US by PGP privacy activists in foreign countries.  There are some restrictions in the US regarding the import of munitions, but I'm not aware of any cases where this was ever enforced for importing cryptographic software into the US.  I imagine that a legal action of that type would be quite a spectacle of controversy.

ViaCrypt PGP is sold in the United States and Canada and is not for export.  The following language was supplied by the US Government to ViaCrypt for inclusion in the ViaCrypt PGP documentation:  "PGP is export restricted by the Office of Export Administration, United

States Department of Commerce and the Offices of Defense Trade Controls and Munitions Control, United States Department of State.  PGP cannot be exported or reexported, directly or indirectly,

(a) without all export or reexport licenses and governmental approvals required by any applicable laws, or

(b) in violation of any prohibition against the export or reexport of any part of PGP."  The

     Government may take the position that the freeware PGP versions are

     also subject to those controls.

The freeware PGP versions 2.5 and 2.6 were released through a posting on a controlled FTP site maintained by MIT.  This site has restrictions and limitations which have been used on other FTP sites to comply with export control requirements with respect to other encryption software such as Kerberos and software from RSA Data Security, Inc.  I urge you not to do anything which would weaken those controls or facilitate any improper export of PGP.

Although PGP has become a worldwide de facto standard for E-mail encryption, and is widely available overseas, I still get calls from people outside the US who ask me if it is legal to use it in their own country, for versions that are already available there.  Please don't contact me to ask me if it is legal to use PGP in your country if you live outside the US.  That question is not up to me.  I've got enough legal problems of my own with export control issues, without getting involved in giving you legal advice over my phone.  It might even put me at some legal risk to simply answer a question like that for a foreigner.  If this question concerns you, ask someone else, like a lawyer.

You may have a need to use PGP in a commercial application outside the US or Canada.  Unfortunately, at the time of this writing, there is no current commercial source for PGP outside the US or Canada.  I am trying to find a US-legal way to make a commercially licensed version available abroad, but right now the US export restrictions make that difficult without putting me at legal risk.  This situation may change.

Some foreign governments impose serious penalties on anyone inside their country for merely using encrypted communications.  In some countries they might even shoot you for that.  But if you live in that kind of country, perhaps you need PGP even more.


Philip Zimmermann's Legal Situation

-----------------------------------

At the time of this writing, I am the target of a US Customs criminal investigation in the Northern District of California.  A criminal investigation is not a civil lawsuit.  Civil lawsuits do not involve prison terms.  My defense attorney has been told by the Assistant US Attorney that the area of law of interest to the investigation has to do with the export controls on encryption software.  The federal mandatory sentencing guidelines for this offense are 41 to 51 months in a federal prison.  US Customs appears to be taking the position that electronic domestic publication of encryption software is the same as exporting it.  The prosecutor has issued a number of federal

grand jury subpoenas.  It may be months before a decision is reached on whether to seek indictment.  This situation may change at any time, so this description may be out of date by the time you read it.  Watch the news for further developments.  If I am indicted and this goes to trial, it will be a major test case. I have a legal defense fund set up for this case.  So far, no other organization is doing the fundraising for me, so I am depending on people like you to contribute directly to this cause.  If you care about the future of your civil liberties in the information age, then

perhaps you will care about this case.  The legal fees are expensive, the meter is running, and I need your help.  The fund is run by my lead defense attorney, Phil Dubois, here in Boulder.

Please send your contributions to:

   Philip L. Dubois, Lawyer

   2305 Broadway

   Boulder, Colorado 80304 USA

   Phone (303) 444-3885

   E-mail:  dubois@csn.org

You can also phone in your donation and put it on Mastercard or Visa. If you want to be really cool, you can use Internet E-mail to send in your contribution, encrypting your message with PGP so that no one can intercept your credit card number.  Include in your E-mail message your Mastercard or Visa number, expiration date, name on the card, and amount of donation.  Then sign it with your own key and encrypt it with Phil Dubois's public key (his key is included in the

standard PGP distribution package, in the "keys.asc" file).  Put a note on the subject line that this is a donation to my legal defense fund, so that Mr. Dubois will decrypt it promptly.  Please don't send a lot of casual encrypted E-mail to him -- I'd rather he use his valuable time to work on my case.

If you want to read some press stories to find out why this is an important case, see the following references:

  1)  William Bulkeley, "Cipher Probe", Wall Street Journal, Thursday

      28 April 1994, front page.

  2)  John Cary, "Spy vs. Computer Nerd:  The Fight Over Data

      Security", Business Week, 4 Oct 1993, page 43.

  3)  Jon Erickson, "Cryptography Fires Up the Feds", Dr. Dobb's

      Journal, December 1993, page 6.

  4)  John Markoff, "Federal Inquiry on Software Examines Privacy

      Programs", New York Times, Tuesday 21 Sep 1993, page C1.

  5)  Kurt Kleiner, "Punks and Privacy", Mother Jones Magazine,

      Jan/Feb 1994, page 17.

  6)  Steven Levy, "Battle of the Clipper Chip", New York Times

      Magazine, Sunday 12 Jun 1994, page 44.

  7)  Steven Levy, "Crypto Rebels", WIRED, May/Jun 1993, page 54.

  8)  John Markoff, "Cyberspace Under Lock and Key", New York Times,

      Sunday 13 Feb 1994.

  9)  Philip Elmer-DeWitt, "Who Should Keep the Keys", Time, 14 Mar

      1994, page 90.

There are a great many other articles on PGP from around the world. I'm keeping a scrapbook.


Where To Get A Commercial Ver. Of  PGP

Where to Get a Commercial Version of PGP

----------------------------------------

To get a fully licensed version of PGP for use in the USA or Canada,

contact:

   ViaCrypt

   9033 North 24th Avenue, Suite 7

   Phoenix, Arizona 85021  USA

   Phone: (602) 944-0773, or (800) 536-2664

   Fax: (602) 943-2601

   E-mail: viacrypt@acm.org

ViaCrypt has a version of PGP for MSDOS, and a number of Unix platforms.  They also have a Windows shell version, and other versions are under development, including Macintosh.  If you have a need to use PGP in a commercial or Government setting, and ViaCrypt has a version of PGP for your hardware platform, you should get ViaCrypt PGP.

ViaCrypt has obtained all the necessary licenses from PKP, Ascom-Tech AG, and Philip Zimmermann to sell PGP for use in commercial or government environments.  ViaCrypt PGP is every bit as secure as the freeware PGP, and is entirely compatible in both directions with the

freeware version of PGP.  ViaCrypt PGP is the perfect way to get a fully licensed version of PGP into your corporate environment.

If you work in a large company and you are a fan of PGP, I urge you to try to persuade your company to buy lots of copies of PGP from ViaCrypt.  Not just because that will earn royalties for me.  If  ViaCrypt can make PGP a commercial success, it will go a long way toward cementing PGP's political future as an unstoppable standard for E-mail encryption in the corporate world.  The corporate world is where the money is, and that affects public policy like nothing else.  And that includes Government policy to suppress strong cryptography.


Reporting Bugs

Reporting PGP Bugs

------------------

Bugs in PGP should be reported via E-mail to MIT, the official distribution site of PGP.  The E-mail address for bug reports is pgp-bugs@mit.edu.  MIT will forward a copy of your bug report to me.  When you report bugs, be sure to specify what machine and operating system you are using and what version of PGP you have, and provide enough detail to reproduce the  problem.  It would also be a good idea to find out if you have the latest version of PGP, in case the bug has already been fixed.  Also, it's a good idea to make sure it really is a bug before you report it.  RTFM.


PGP Fan Mail

Fan Mail, Updates, and News

---------------------------

After all this work I have to admit I wouldn't mind getting some fan mail for PGP, to gauge its popularity.  Let me know what you think about it and how many of your friends use it.  Bug reports and suggestions for enhancing PGP are welcome, too.  Perhaps a future PGP release will reflect your suggestions.

This project has not been funded and the project has nearly eaten me alive.  This means you usually won't get a reply to your mail, unless you only need a short written reply and you include a stamped self-addressed envelope.  But I often do reply to E-mail.  Please keep it in English, as my foreign language skills are weak.  If you call and I'm not in, it's best to just try again later.  I usually don't return long distance phone calls, unless you leave a message that I can call you collect, and even then I might not return your call.  If you need any significant amount of my time, I am available on a paid consulting basis, and I always return those calls.

The most inconvenient mail I get is for some well-intentioned person to send me a few dollars asking me for a copy of PGP.  I don't send it to them because I'd rather avoid any legal problems with PKP.  Or worse, sometimes these requests are from foreign countries, and I

would be risking a violation of US cryptographic export control laws.  Even if there were no legal hassles involved in sending PGP to them, they usually don't send enough money to make it worth my time. I'm just not set up as a low cost low volume mail order business.  I can't just ignore the request and keep the money, because they probably regard the money as a fee for me to fulfill their request. If I return the money, I might have to get in my car and drive down to the post office and buy some postage stamps, because these requests rarely include a stamped self-addressed envelope.  And I have to take the time to write a polite reply that I can't do it.  If I postpone the reply and set the letter down on my desk, it might be buried within minutes and won't see the light of day again for months.  Multiply these minor inconveniences by the number of requests I get, and you can see the problem.  Isn't it enough that the software is free?  It would be nicer if people could try to get PGP from any of the myriad other sources.  If you don't have a modem, ask a friend to get it for you.  If you can't find it yourself, I don't mind answering a quick phone call.

If anyone wants to volunteer to improve PGP, please let me know.  It could certainly use some more work.  Some features were deferred to get it out the door.  A number of PGP users have since donated their time to port PGP to Unix on Sun SPARCstations, to Ultrix, to VAX/VMS,

to OS/2, to the Amiga, and to the Atari ST.  Perhaps you can help port it to some new environments.  But please let me know if you plan to port or add enhancements to PGP, to avoid duplication of effort, and to avoid starting with an obsolete version of the source code.

Because so many foreign language translations of PGP have been produced, most of them are not distributed with the regular PGP release package because it would require too much disk space.  Separate language translation "kits" are available from a number of independent sources, and are sometimes available separately from the same distribution centers that carry the regular PGP release software.  These kits include translated versions of the file LANGUAGE.TXT, PGP.HLP, and the PGP User's Guide.  If you want to produce a translation for your own native language, contact me first to get the latest information and standard guidelines, and to find out if it's been translated to your language already.  To find out where to get a foreign language kit for your language, you might check on the Internet newsgroups, or get it from Mike Johnson (mpj@csn.org).

If you have access to the Internet, watch for announcements of new releases of PGP on the Internet newsgroups "sci.crypt" and PGP's own newsgroup, "alt.security.pgp".  If you want to know where to get PGP, MIT is the primary FTP distribution site (net-dist.mit.edu).  Or ask Mike Johnson (mpj@csn.org) for a list of Internet FTP sites and BBS phone numbers.


Computer-Related Political Groups

---------------------------------

PGP is a very political piece of software.  It seems appropriate to mention here some computer-related activist groups.  Full details on these groups, and how to join them, is provided in a separate document file in the PGP release package.

The Electronic Privacy Information Center (EPIC) is a public interest research center in Washington, DC.  It was established in 1994 to focus public attention on emerging privacy issues relating to the National Information Infrastructure, such as the Clipper Chip, the Digital Telephony proposal, medical record privacy, and the sale of consumer data.  EPIC is sponsored by the Fund for Constitutional Government and Computer Professionals for Social Responsibility. EPIC publishes the EPIC Alert and EPIC Reports, pursues Freedom of Information Act litigation, and conducts policy research on emerging privacy issues.  For more information email info@epic.org, or write EPIC, 666 Pennsylvania Ave., SE, Suite 301, Washington, DC 20003. +1 202 544 9240 (tel), +1 202 547 5482 (fax).

The Electronic Frontier Foundation (EFF) was founded in 1990 to assure freedom of expression in digital media, with a particular emphasis on applying the principles embodied in the US Constitution and the Bill of Rights to computer-based communication.  They can be reached in Washington DC, at (202) 347-5400.  Internet E-mail address: eff@eff.org.

Computer Professionals For Social Responsibility (CPSR) empowers computer professionals and computer users to advocate for the responsible use of information technology and empowers all who use computer technology to participate in public policy debates on the

impacts of computers on society.  They can be reached at: (415) 322-3778 in Palo Alto, E-mail address cpsr@csli.stanford.edu.

The League for Programming Freedom (LPF) is a grass-roots organization of professors, students, businessmen, programmers and users dedicated to bringing back the freedom to write programs.  They regard patents on computer algorithms as harmful to the US software industry (and so do I!).  They can be reached at (617) 433-7071.  E-mail address: lpf@uunet.uu.net.

For more details on these groups, see the accompanying document in the PGP release package.


Recommended Reading

Recommended Readings

--------------------

Introductory Readings

1)  Bruce Schneier, "Applied Cryptography: Protocols, Algorithms, and

    Source Code in C", John Wiley & Sons, 1993

    (This book is a watershed work on the subject.)

2)  Dorothy Denning, "Cryptography and Data Security", Addison-Wesley,

    Reading, MA 1982

3)  Dorothy Denning, "Protecting Public Keys and Signature Keys",

    IEEE Computer, Feb 1983

4)  Martin E. Hellman, "The Mathematics of Public-Key Cryptography,"

    Scientific American, Aug 1979

5)  Steven Levy, "Crypto Rebels", WIRED, May/Jun 1993, page 54.

    (A "must-read" article on PGP and other related topics.)

6)  Steven Levy, "Battle of the Clipper Chip", New York Times

    Magazine, Sunday 12 Jun 1994, page 44. (Great article, great

    photos.)

7)  William Bulkeley, "Cipher Probe", Wall Street Journal, 28 April

    1994, front page.  (An article on PGP and Zimmermann.)

Other Readings

8)  Ronald Rivest, "The MD5 Message Digest Algorithm", MIT Laboratory

    for Computer Science, 1991

9)  Xuejia Lai, "On the Design and Security of Block Ciphers",

    ETH Series on Information Processing (Ed. J. L. Massey),

    Vol. 1, Hartung-Gorre Verlag, Konstanz, Switzerland, 1992

10) Philip Zimmermann, "A Proposed Standard Format for RSA

    Cryptosystems", Advances in Computer Security, Vol III, edited by

    Rein Turn, Artech House, 1988

11) Paul Wallich, "Electronic Envelopes", Scientific American, Feb

    1993, page 30.  (An article on PGP)

12) William Stallings, "Pretty Good Privacy", BYTE, July 1994, page

    193

13) Philip Zimmermann, "The Official PGP User's Guide", MIT Press,

    1994 (in press)

14) Philip Zimmermann, "PGP Source Code and Internals", MIT Press,

    1994 (in press)


To Contact PGP Author

To Contact the Author

---------------------

Philip Zimmermann may be reached at:

Boulder Software Engineering

3021 Eleventh Street

Boulder, Colorado 80304  USA

Internet:  prz@acm.org

Phone (303) 541-0140 (voice)  (10:00am - 7:00pm Mountain Time)

Fax available, if you arrange it via voice line.


Where To Get PGP

Appendix A:  Where to Get PGP

=============================

The following describes how to get the freeware public key cryptographic software PGP (Pretty Good Privacy) from an anonymous FTP site on Internet, or from other sources.

PGP has become a worldwide de facto standard for E-mail encryption. PGP has sophisticated key management, an RSA/conventional hybrid  encryption scheme, message digests for digital signatures, data compression before encryption, and good ergonomic design.  PGP is well featured and fast, and has excellent user documentation.  Source code is free.

The Massachusetts Institute of Technology is the distributor of PGP version 2.6, for distribution in the USA only.  It is available from "net-dist.mit.edu," a controlled FTP site that has restrictions and limitations, similar to those used by RSA Data Security, Inc., to comply with export control requirements.  The software resides in the directory /pub/PGP.

A reminder:  Set mode to binary or image when doing an FTP transfer. And when doing a kermit download to your PC, specify 8-bit binary mode at both ends.

There are two compressed archive files in the standard release, with the file name derived from the release version number.  For PGP version 2.6.2, you must get pgp262.zip which contains the MSDOS binary executable and the PGP User's Guide, and you can optionally get pgp262s.zip which contains all the source code.  These files can be decompressed with the MSDOS shareware archive decompression utility PKUNZIP.EXE, version 1.10 or later.  For Unix users who lack an implementation of UNZIP, the source code can also be found in the compressed tar file pgp262s.tar.Z.

If you don't have any local BBS phone numbers handy, here is a BBS you might try.  The Catacombs BBS, operated by Mike Johnson in Longmont, Colorado, has PGP available for download by people in the US or Canada only.  The BBS phone number is 303-772-1062.  Mike

Johnson's voice phone number is 303 772-1773, and his E-mail address is mpj@csn.org.  Mike also has PGP available on an Internet FTP site for users in the US or Canada only; the site name is csn.org, in directory /mpj/, and you must read the README.MPJ file to get it.

To get a fully licensed version of PGP for use in the USA or Canada, contact ViaCrypt in Phoenix, Arizona.  Their phone number is 602-944-0773.  ViaCrypt has obtained all the necessary licenses from PKP, Ascom-Tech AG, and Philip Zimmermann to sell PGP for use in commercial or Government environments.  ViaCrypt PGP is every bit as secure as the freeware PGP, and is entirely compatible in both directions with the freeware version of PGP.  ViaCrypt PGP is the

perfect way to get a fully licensed version of PGP into your corporate or Government environment.

Here are a few people and their E-mail addresses or phone numbers you can contact in some countries to get information on local PGP availability for versions earlier than 2.5:

Peter Gutmann                 Hugh Kennedy

pgut1@cs.aukuni.ac.nz         70042.710@compuserve.com

New Zealand                   Germany

Branko Lankester              Miguel Angel Gallardo

branko@hacktic.nl             gallardo@batman.fi.upm.es

+31 2159 42242                (341) 474 38 09

The Netherlands               Spain

Hugh Miller                   Colin Plumb

hmiller@lucpul.it.luc.edu     colin@nyx.cs.du.edu

(312) 508-2727                Toronto, Ontario, Canada

USA

Jean-loup Gailly

jloup@chorus.fr

France


Release Notes

The following information is a brief description on version releases of The Secure Mail System.

10/08/98

1.	Fixed bug in e-page delivery

2.	Fixed bug in Leave On Server, Would keep retrieving same mail.

3.	Added option to allow notification control.

4.	Added Maximum Length to e-pages.

5.	Changed Registration Key Structure.

09/29/98 Version 2.5.3

1.	Changed New Mail Mail Box indicator to make new mail locating easier.

2.	Added deselect default signature and V-Card.

3.	Added the ability to move mail folders.

4.	New Mail Boxes are now updating correctly.

5.	Window Sizes are now being retained.

09/20/98 Version 2.5.2

1.	Application Title was incorrect when minimized.

2.	Fixed Dial-Up Profile, was not being displayed.

3.	Fixed problem with new account setup, caused occasional error of Provider Not installed.

4.	Removed AOL Sound Files.

5.	Multiple Accounts would cause a redial for each account, now only dials once.

6.	Added Message Sorting in main Message Listing by clicking on caption.

7.	Drop and Send To are now working correctly, would cause an access violation before.

8.	Default Account is now automatically set to first created account.

9.	Fixed problem with PGP Key Naming when a space was in the User Name.

10.	Fixed problem with Time Conversion in Scheduler.

11.	Address now can be added from a message.

08/22/98 Version 2.5

1.	Added Multiple Provider Support.

2.	Added V-Card Support.

3.	Added Multiple Signature Selection.

4.	Added Tool Bar For RTF Files.

5.	Changed Address Book to handle V-Card Support.

6.	Stream Lined Indexing routines for faster indexing.

7.	New Messages are now listed at top of message listings.

8.	HTML Tags are automatically removed for easier viewing of HTML Messages.

9.	SMTP Servers are now accessed only when mail is being sent.

10.	Message Lists now show when files are attached to a message.

11.	Added Pager Notification.

12.	Messages can be forwarded to pager.

13.	Added Secret Key updating to key manager.

14.	Added Quick Access Icons to System Tray.

15.	Fixed problems with some of the windows hiding behind others.

16.	Fixed problem with List Index Out Of Bounds on some messages.

17.	Fixed problems with some file not being found when default directory was not being used.

18.	Fixed Access Violation when deleting folders.

19.	Fixed View Headers in Compose Window was not working.

20.	Fixed Arrow movement up/down on message list.

21.	Fixed Arrow movement up/down on folders list.

22.	Fixed problem with decoding Multipart/Alternitive Messages.

23.	Fixed problem with manual address entry on a Audio Message.

24.	Fixed Access Violation when Delete Button is pressed rapidly.

25.	Fixed problem with spaces when attaching PGP Keys to a message.

26.	Fixed problem with verifying detached signatures.

04/01/98 Version 2.3

Applications were updated to reflect the new Web Hosts.

10/25/97 Version 2.3

1.	Added a PGP Trouble Shooter option to aid in problem solving of PGP Error.

2.	Cleaned up some code.

10/19/97 Version 2.2

1.	Fixed Access Violation problem when OK is pressed in the PGP Configuration Screen.

2.	Fixed problem with empty key ring list when encrypting to a non-pgp addressed user.

10/11/97 Version 2.1

1.	Fixed problem where PGP keys were not being displayed during encryption proccess where a key was not found in the address book.

2.	More internal changes to source to accommodate Pro Version.

10/02/97 Version 2.0

1.	Fixed problem with extracting keys in Key Manager.

2.	Changes to source to accommodate Pro Version.

09/23/97 Version 1.9

1.	Fixed problem with not being able to certify a key that is on your key ring.

2.	Fixed problem with not being able to copy secret key to disk option.

3.	Address Book File/Exit now works.

4.	Key Manager File/Exit now works.

5.	Allow case now in compose mail address field.

6.	Added the ability to lookup address by name in the current address book when partial unique name is entered on the address line of the compose mail screen.

09/12/97 Version 1.8

1.	PGP.BAT file now gets deleted when not in use.

2.	Copy option on Compose Mail Form now working.

3.	All PGP Error are now captured.

4.	Key Manager now extracts and removes Secret Keys correctly.

5.	Added manual entry of PGP Pass Phrase.

6.	Case now is retained when renaming mailboxes.

7.	Fixed minor problem when messages get deleted in Leave On Server Option.

8.	Window and Icon now flash to indicate you have new mail.

9.	Fixed Winsock not loaded exception on occasion when program gets terminated.

10.	Port error when using more the one ISP connection fixed.

09/08/97 Version 1.75

1.	Fixed problem with Leave On Server Option when deleting expired messages.

2.	Occasionally PGP would ask if it were ok to overwrite pgpmsg.asc.

3.	Occasional Access Violation when adding PGP information to Address Book.

4.	When message was saved in the Draft Folder, it was not being indexed correctly.

5.	Problem when duplicated MailBox Names are used now fixed.

6.	Fixed problem with last message not being imported from Netscape’s mail folder.

7.	Fixed problem with not being able to rename Address Books and Group Lists.

8.	Fixed problem with duplicating Key list in Key Ring Manager when adding keys.

9.	When replying to a non-PGP Message, PGP options would not enable.

10.	Sent & Draft Folder now shows who message is being sent to.

11.	Occasional problem with PGP Configuration not found when attaching a public key.

12.	PGP Key List did not update after removing a key from the key ring.

13.	PGP Options now available when editing messages.

14.	Outbound and Sent message dates now correct.

09/04/97 Version 1.7

1.	Fixed intermittent disabling of PGP Options while composing mail.

2.	You can now edit messages correctly once they have been saved.

3.	Message Lists now get updated correctly when a saved message gets edited.

4.	Fixed screen size problem when using large fonts.

5.	Added Importing of Netscape 3.0 and HTML address to the Address Book.

6.	Added Importing of messages from Netscape 3.0 Message File.

7.	Secure Mail now minimizes to the System Tray with quick access menu.

09/01/97 Version 1.61

1.	Fixed bug in manual decryption/encryption. (was not allowing access to option all the time)

2.	Fixed bug with not being able to access Mailer/PGP Setup with a long user name after a call to the server has been done.

3.	Fixed intermittent Winsock Not Loaded problem.

4.	Fixed minor display problems.

5.	Fixed Messages counters when using Leave On Server Option.

6.	Added new Update Program, allowing for easy retrieval of ISS Software and Updates.

08/25/97 Version 1.6

1.	Changed Message Folders to Mail Boxes with unread mail indication. This is useful when you filter messages.

2.	Added Leave On Server option and Remote POP Operation.

3.	Added Save File Attachment option to Message Filtering.

4.	Added Send/Receive only options.

5.	Added Expand/Collapse All function to Folder Viewer.

08/19/97 Version 1.5

1.	PGP Key routines are now in the Key Manager. This was done for ease of implementation of PGP 5.0 in late September or October.

2.	Added default Address Books and Message Filters.

3.	Fixed bug with message filtering.

4.	Fixed some bad links in Help File.

08/12/97 Version 1.4.1

1.	Fixed bug when viewing next/prev. message.

2.	Changed the Add PGP Key to message to allow for you to add more then one key at a time.

3.	Fixed bug in Address Book that caused Secure Mail not to automatically find the PGP key when sending a PGP Message.

4.	Added Next/Prev. and delete current option to Message Editor.

5.	Added Forward option to Message Filtering.

6.	Changed E-Mail addressing field so they are not case sensitive.

7.	Added Sub Folders option to Message Folders.

8.	Enabled Scanner Support.

9.	Added Voice Messaging Support.

10.	Added Prompt Options.

11.	Minor bug fixes.

08/11/97 Version 1.3

1.	Fixed problem with Forward Message option.

2.	Fixed incoming message indexing problem.

3.	Fixed problem with auto decrypt.

4.	Increased MIME/UU encoded/decode 2 to 3 times.

5.	This update took care of some problems when encrypting with multiple recipients.

6.	Added Scanner Support (Not Enabled Yet).

7.	Cleaned up windows and added operation tags.

8.	Added Auto Operation Selection when (PGP,KEY,and Sif 'Scaned Image File') double clicking attachments.

9.	Added Auto Deleting of files on exit option. Added Unread Message Notification on Startup.

08/7/97 Version 1.2

1.	Fixed bug in Indexing of messages.

2.	Added Plain Text option to Message Editor.

3.	Added Formatting support to Message Editor.

4.	Added Search routines to Message Editor.

5.	Window aspect now saved.

6.	Added Organization option to setup.

7.	Added Zip Manager.

8.	Added Image Viewer.

9.	Added Multiple User Option.

08/3/97 Version 1.1

1.	Fixed Auto Decrypt bugs.

2.	Added Scheduler.

3.	Added Message Filtering.

4.	Added Backup/Restore Option.

5.	Added Multiple Address Books.

07/30/97 Version 1.0

Initial Release!


Virus Scanning

If you have a virus scanner installed on your system that excepts command line parameters, then you can have The Secure Mail System scan file attachments for viruses to help insure that your system remains virus free. The following items can be found on the Virus Scanning Tab.

Virus Scan Application:

This is the location of the virus scanner application file. No Parameters!

Command Line Parameters:

This is the parameter use to scan the file attachment directory and other option you would like to set during the scan. Secure Mail will automatically set the directory for the attachment directory, all you need to set is the file search wild cards. If your Virus scanner supports report generation, then you can use the <REPORT> macro to view the report after a scan. Below is an example of parameter for a McAfee Virus Scanner:

        /CLEAN /REPORT <REPORT> /RPTALL /RPTCOR *.*

The above line would scan all files in the attachment directory, clean any infected files generate a report to be viewed after the scan, and report on all scanned files including corrupted ones.

Enable Virus Scanning:

When checked, virus scanning will be enabled.

Scan Unread Msgs. Only:

When checked, will only scan for viruses if the message is marked unread.

Run Scan Minimized:

When checked, Secure Mail will minimize the virus scan window. This option is useful if you do not have a report option on you scanner and need to view the output of the scan results.


Main Screen Overview;Overview

Main Screen Overview

This screen is the heart of the entire mailer, from here you can access all sub systems of the mailer, manage all messages and folders, manage all your PGP keys, system configuration, mail transfers, and more. Read the following sub categories for information on what this entire screen has to offer.

Related Topics:

Main Menu Bar:

File

Folders

Messages

PGP

Setup

Window

Help

Icon Bar:

Items On Icon Bar

Folder List Box:

Message Folder Overview

Folders & Messages

Message List Box:

Message List Box Overview

Message Icons

Status Bar:

Status Bar Overview


Window Menu Item

This menu contains sub programs that can be accessed through The Secure Mail System. The following items can be found on this menu.

Zip Manager:

This will start the Zip Manager utility program. This utility allows you to manage zip files with ease. For more information on using the Zip Manger see the Zip Manager Help File.

Image Viewer:

The Image Viewer allows you to view JPG, GIF, BMP, and SIF images. For more information, see Image Viewer Help.

Audio Recorder:

The Audio Recorder allows you to record audio messages and save them in MSF Format. For more information see Sound Recorder Help.

Image Acquisition:

This option allows you to acquire images from a Twain Compliant Scanner and save them in BMP, GIF, or SIF Format. For more information see Image ScannerError! No bookmark name given..


Composition Edit Menu

This menu is for aiding you in editing your message. All these menu items can also be found on the Icon Bar. The following items are available from this menu.

Cut:

This will cut the selected text and stores it on the clipboard.

Copy:

This will copy the selected text to the clipboard.

Paste:

This will paste the information that is stored on the clipboard at the cursors current location.

Note: The Paste item is only active if there is something on the clipboard to paste.

Delete:

This will delete the selected text from the message.

Find:

This option allows you to enter a desired word or string to find in the message.

Find Next:

This option repeats the last find command.

Search & Replace:

This option allows you to find and replace a desired word or string in your message.

Spell Check:

This will spell check your message. If you have selected Auto Spell Check in Mailer Setup under the Composition Tab, you should not have to use this option.

Spell Check Setup:

This will display the Spell Check setup dialog box. From here you can change the way the spell checker functions.

Thesaurus:

This will bring up the Thesaurus.


Composition Icon Bar

The Composition Icon bar is a quick access tool to commonly used menu items. The following icons are listed in order from left to right.

Send:

This will validate your message (Check to make sure all necessary fields have correct data), then it will spell check the message (Default Enabled), it will then add your Signature File if you have chosen one in the Mailer Setup under the Identity Tab,  then store the message in the Out Box for delivery.

Note: This Item will not become available until a recipient’s e-mail address has been specified.

Save Draft Copy:

This will save the message in the Draft Folder for later completion. This is useful if you need to  a long letter at a later time or using the same letter for different reasons.

Default Sign & Send:

This item does the same as the Send and will also sign the message with your PGP Signature. This is useful for tamper protection and validity of a message. The Default Signature is used for this and can be set in the PGP Setup under the Advanced Options Tab.

Note: This item is only available if PGP has been installed.

Default Encrypt & Send:

This item does the same as the Send and will also Encrypt the message with the recipients PGP Public Key. This is useful for tamper protection and unauthorized access to the message. The Default Encryption is used for this and can be set in the PGP Setup under the Advanced Options Tab.

Note: This item is only available if PGP has been installed.

Discard:

This will send the current message to the Trash Folder.

Attach A File:

This allows you to attach one or more files to the current message. This will bring up a dialog box so you can select the file or files that you want to attach.

Reply To Message:

This is used for replying to the current message you are viewing. A new message composition screen will be created with the recipient’s address already filled in. If you have chosen to Quote the original message (See Composition Tab in Mailer Setup), it will be appended to your new message. This aids in keeping on track of the conversation.

Forward This Message:

This will allow you to pass the current message on to another person. This is useful if you receive a message that does not really pertain to you but know the person that it does.

View Message Header:

Selecting this option will allow you to view the Internet Message Header of the selected message. Viewing this header can tell you where the message has been and for how long. Useful for tracing messages.

Decrypt Message:

This option will decrypt the current message. If you are not the key holder of this message, you will get an error that the decrypted message was not found and then you will see a message box indicating that you are not the key holder of this message. If the message has been signed, a validity check will be done on the message to ensure that it has not been tampered with. If the message is in good standing you will receive a message indicating that you have a good signature.

NOTE: Sometime a server will strip off trailing spaces or lines, if this happens, you will get a bad signature warning.

Verify Signature:

This will verify a Attached Signature to validate the authenticity of the message.

Cut:

This will cut the selected text and stores it on the clipboard.

Copy:

This will copy the selected text to the clipboard.

Paste:

This will paste the information that is stored on the clipboard at the cursors current location.

Note: The Paste item is only active if there is something on the clipboard to paste.

Delete Text:

This will delete the selected text from the message.

Find:

This option allows you to enter a desired word or string to find in the message.

Find & Replace:

This option allows you to find and replace a desired word or string in your message.

Spell Check:

This will spell check your message. If you have selected Auto Spell Check in Mailer Setup under the Composition Tab, you should not have to use this option.

Thesaurus:

This will bring up the Thesaurus.

Print:

This prints the current message on your printer.

Discard & Get Previous Message:

This option allows you to discard the current message and view the previous message in the Message List Box.

Discard & Get Next Message:

This option allows you to discard the current message and view the next message in the Message List Box.

Get Previous Message:

This option allows you to view the previous message in the Message List Box.

Get Next Message:

This option allows you to view the next message in the Message List Box.


File Attchment Menu

Composition File Attachment Menu

The file attachment menu is for you to be able to attach or copy files to and from your messages. There are four types of file attachments you can do, they are, and normal files attachments, encrypted file attachment, public key attachments and zipped file attachments. They are explained in more detail below. If you right click your mouse while in the File Attachment window, a pop up version of this menu will be displayed.

Add File Attachment:

This option will display the open dialog box (directories/files ect). From this dialog box select the file you wish to add as a file attachment.

Create & Attach New Zip File:

This option allows you to create a zip file and automatically attach the zip file to your message. See Zip Manager Help for more information on this topic.

Encrypt & Add File Attachment:

This option will display the open dialog box. From this dialog box select the file you wish to encrypt and add as a file attachment. The selected file will be encrypted to all recipients of the current message and attached to the message.

NOTE: You must have all the addressees you want this message to be sent to prior to encrypting a file attachment or one or more of the later added addressees will not be able to decrypt the message. You must also specify what type of file it is in the message body so the recipient will know what to save the file as. (E.g. time.pgp should be saved as time.exe)  This feature is only active when PGP is installed.

Attach Public Key:

This option allows you to select a public key from your public key ring and attach it to the message. This is useful to easily exchange keys with others.

Attach V-Card:

This option will allow you to add a V-Card from a contact in your address book.

Add V-Card To Address Book:

This option will add the selected V-Card to your address book.

Attach Audio Message:

This option will display the Audio Recorder, which will enable you to record and attach an audio message to your e-mail message. Note: Audio messages can become quite large very quickly. A 1 Min. message takes up about 225K of disk space. You have about a 4 Minute Limit. This may be increased in the future. Keep in mind that most Internet Service Providers have a limit on the size of message that can be received.

Attach Encrypted Audio Message:

This option will display the Audio Recorder, which will enable you to record and attach an encrypted audio message to your e-mail message. Note:  Encrypted audio messages can become quite large very quickly. A 1 Min. message takes up about 440K of disk space. You have about a 4-Minute Limit. This may be increased in the future. Keep in mind that most Internet Service Providers have a limit on the size of message that can be received.

Acquire Image & Attach Encrypted:

This option allows you to scan an image from a Twain compliant scanner and directly encrypt and attach the scanned image to your message.  Note: The scanned image will automatically be reduced to 50% of its original size. This will reduce the size of the image file but will still be able to view the image in aspect of your monitor. If you are sending documents, use the BW or Line Art setting of your scanner to keep the image size to a workable size. If the document will be printed out on the recipient’s end, resize the image back to 100% before attaching the image to the message. Encrypting will increase the file size dramatically.   A typical 8 ½ X 11 BW image at 100% and 300 dpi will result in a file size of about 111K. A Polaroid scanned in color at 50% and 300 dpi will result in a file size of about 19K. When attaching images keep in mind that most Internet Service Providers have a limit on the size of message that can be received.

Save File Attachment:

This option allows for you to save the selected file attachment. This will not remove the attachment from the message. A save dialog box will appear, then select the location where you want the file to be saved to.

Delete File Attachment:

This option will delete the selected file from the message. Be sure you have saved the attachment first.

Run File Attachment:

This option will run the associated program for this attachment. For example, if the attached file were a .TXT file, then Notepad would start and display the text file for you. The icon of the file attachment will show its association if on is present. In the above example, the icon for the text file would be the Notepad Icon.

NOTE: By double clicking on the icon, the Run File Attachment option is automatically selected.

Add PGP Key To Public Key Ring:

If you wish add a key to your keyring simply right click within the file attachment area and if the key is there then simply click ‘add key to public key ring”. The key will be added to your public ring. If you wish to receive a public key it is best that it is sent via a file attachment.

NOTE: If the key does not pass your certification setting that you have selected in Advanced PGP Option then you will have to certify the key.

Decrypt PGP Attachment:

This option allows you to decrypt and save a file attachment that has been encrypted. If a file has been encrypted, a lock icon will appear above the file name. If you try to decrypt a file that is not meant for you, a error will appear and information on who the file is actually is for. When the Save Dialog Box appears, set the save as type to the correct file type before saving. You can double click the icon to automatically select the Decrypt PGP Attachment option.

Properties:

This option will display the Properties Dialog Box. This dialog box contains information on the file type and size information. This is a useful tool to keep messages within file size limitations of the recipients ISP.


Account Selection

The account selection drop-down box allows you to select which Internet Account you wish to use to send the current message. You must set-up at least one account before you are able to send a message. See Account Set-up to learn on how to setup an account.


Signature Selection

The Signature selection drop-down box allows you to select which Signature you wish to add to the end of the message. See Signature Set-up to learn on how to setup Signatures.


Signature Selection

V-Card Selection

The V-Card selection drop-down box allows you to select which V-Card if any you wish to add to message. See V-Card Set-up to learn on how to setup V-Card.


General Setup

General Setup Information

When you first start The Secure Mail System, you will be warned that the configuration information is not found.  The configuration is the information that The Secure Mail System needs to connect to your provider, If PGP is installed etc. Click the OK Button and continue with the setup. Once the setup dialog box appears, you can select from one of the following tabs.

See the following topics:

Composition

Passwords

Options

Pager


Pager Setup

Pager Setup Information

You can be notified via a pager of new messages. This feature will only work for alphanumeric pagers and the Service Provider’s Terminal must be TAP compliant. In order for this feature to work, you will need to get some information from your Pager Service Provider. This would be the Modem Access Number, Password if any, Protocol Settings, and your PIN if it differs from your Pager Number. This feature will also work for Digital Cellular phone as long as the Short Messaging System conforms to the TAP Protocol.

Modem Type:

Select your modem type from the list. If your modem is not on the list, try the generic or Hays compatible modem setting. If this dose not work, you may need to read the documentation for your modem to get the correct modem initialization string before this option will work correctly.

Init. String:

This is the modem initialization string. This will be set for you when you select a modem type. You may need to modify these settings before this feature will work correctly.

Flow Control:

This is the Flow Control setting for your modem. Normally this will be Hardware. This option must follow the flow control setting that is used in your initialization string. See your modem documentation for more information.

Com Port:

This is the Com Port for your modem. This cam be found in your control panels under modems, if you are unsure of the setting.

Modem Speed:

This is the maximum speed that your modem will operate at. Normally 19200 for a 14.4 modem and 38400 if a 33.6 modem.

Access Number:

This is the modem number for your Pager Service Provider. You will need to contact your Provider to get this number.

Password:

This is the password to access the paging terminal. Normally this will be left blank, however some providers require one. You will need to contact your Provider to get this Password.

Parity, Stop Bits, Data Bits:

These are protocol settings for the paging terminal. Normally these will not need to be changed. Normally the will be set to Even, One, Seven. You will want to ask your provider to make sure these settings are correct.

Length:

This is the maximum length that the Paging Terminal will accept per message. Most pagers will accept up to 240 characters and Cellular phones only 80 or 140 per message. You will want to ask your provider for this information.

Max Length:

This is the maximum character length that is allowed for an E-Mail Page. Should a E-Mail Page exceed this amount, the page will not be sent and will just be stored in the Mail Box you you have selected to send the filtered messages to.

PIN:

This is your Personal Identification number. This is normally your pager number but may not be as with AT&T Cellular Phones.

P.N. Enable:

Check this option if you wish to enable the Pager Notification Feature.


Main Menu File

File Menu Item

This menu item contains the major function for The Secure Mail System. The items and a brief explanation of there function is listed below.

Compose Mail Message:

Select this option to compose a new e-mail message. This will bring up the e-mail message editor. See Composing E-Mail for more information on this topic.

Compose Voice Message:

Select this option to compose a new voice message. This will bring up the voice message editor. See Voice Message for more information on this topic.

Address Book:

Selecting this option will bring up your Address Book. This is where you can store information about people you exchange e-mail messages with. See Address Book for more information on this topic.

Call Server:

Select this option to connect to the mail server and transfer mail. This will first dial the server and log you on to the network (If not using a local LAN connection), then will check and download any new mail, next it will check for forwarding options, and finally send all outgoing messages. During the connection you can monitor the progress by viewing the progress information on the Status Bar at the bottom of Secure Mail’s main window.

Call Server & Send Outgoing:

Select this option to connect to the mail server and transfer out going mail only. This will first dial the server and log you on to the network (If not using a local LAN connection), then will send all outgoing messages. During the connection you can monitor the progress by viewing the progress information on the Status Bar at the bottom of Secure Mail’s main window.

Call Server & Retrieve Incoming:

Select this option to connect to the mail server and transfer Incoming mail only. This will first dial the server and log you on to the network (If not using a local LAN connection), then will receive all incoming messages. During the connection you can monitor the progress by viewing the progress information on the Status Bar at the bottom of Secure Mail’s main window.

Remote POP Control:

This option will allow you to remotely manage your messages on the server. This is useful if you are using the Leave On Server option on and you wish to retrieve a deleted message from the server or just to message cleanup. See Remote POP Operation for more information on this topic.

Cancel Call:

Selecting this option will cancel the current call and transfer progress. Use the option cautiously as loosing data could occur.

View Logs:

Selecting this option allows you to view your Send and Receive Logs. All communications between the server and the mailer are logged in these logs.

Printer Setup:

Selecting this option will allow you to make changes to the printer settings.

Backup Files:

This option allows you to backup all critical information. See Backing Up Data Files for more information.

Restore Files:

This option allows you to restore lost or corrupted data files. Must have a previously backed up data file. See Restoring Data Files for more information.

Make Default Mailer:

This option will make The Secure Mail System your default mailer. When you click on a MailTo Link, in your Web Browser, you will use Secure Mail to send your message.

Exit:

Selecting this option will terminate the application.


Folder Menu Item

This menu deals with managing your message folders. The following is a list of options you can access using this menu. This menu can also Pop Up when you right click your mouse while the mouse is in the Folder List Box.

New Root Folder:

This will pop up a dialog box asking for a new root folder name. Enter the name of the new folder and click OK. A new root folder will be created in the Folder List Box.

New Sub-Folder:

This will pop up a dialog box asking for a new sub-folder name. Enter the name of the new folder and click OK. A new sub-folder will be created under the currently selected folder in the Folder List Box.

Delete Folder:

This will delete the selected folder and all messages that it contains. You will not be able to delete the yellow folder, as they are system folders. However you can delete the blue folders.

NOTE: The Delete Folder option will only become active when a valid folder is selected. You must delete all sub-folders below the folder you wish to delete first.

Reindex:

This is a maintenance function that will check the message indexing in the selected folder. At times it may be necessary to use this if a your system crashed. You should not have to use this as The Secure Mail System checks the indexing at startup.

Rebuild Index:

This is also a maintenance function but more radical then the Reindex method that is mentioned above. This will totally rebuild all indexes. By doing so, all messages will be marked as unread.

Expand All:

This will expand and show all trees in the Folder Window.

Collapse All:

This will collapse all Trees in the Folder Window and shows only the Root Folders.

Import:

From Netscape 3.0:

This option will allow you to import messages from Netscape 3.0 message base. After selecting this option go to your Netscape\Navigator\Mail folder and select the file that matches the folder name in Netscape you wish to import. The file will not have an extension!. E.G. \Program Files\Netsacpe\Navigator\Mail\InBox would import all messages from the In Box folder from Netscape.

From Eudora:

This option will allow you to import messages from Eudora message base. After selecting this option go to your Eudora folder and select the file that matches the folder name in Netscape you wish to import. The file will have an extension of .mbx.

Empty Trash:

This will permanently delete all messages in the trash folder. Use caution when executing this option.


Setup Menu Item

Settings Menu Item

This menu item allows you access to the four setup areas of The Secure Mail System. The following options are available from this menu item.

Mailer Setup:

Selecting this option will take you to the Mailer Configuration Screen. See Mailer Setup for more information on this topic.

Msg. Filter:

Selecting this option will take you to the Message Filter Configuration Screen. See Message Filtering for more information on this topic.

Scheduler:

Selecting this option will take you to the Scheduler Configuration Screen. See Scheduler Setup for more information on this topic.

Accounts:

Selecting this option will take you to the Account Setup Screen. See Account Setup for more information on this topic.

Signatures:

Selecting this option will take you to the Signature Setup Screen. See Signature Setup for more information on this topic.

V-Cards:

Selecting this option will take you to the V-Card Setup Screen. See V-Card Setup for more information on this topic.


Composition Screen Overview

This screen is used to compose or edit messages. The editor is a small word processor that will enable you to write professional looking letters. It even includes a Spell Checker and a Thesaurus. File attachments are easily done with just a couple of mouse clicks and all your e-mail friends can be easily maintained in the Address Book.

 Related Topics:

Composition Menu Bar:

Message

File Attachments

Edit

PGP Message

Format

Help

Composition Icon Bar:

Icons On Bar

Addressing Information Block:

Address Button

Addressing Type

E-Mail Address

Address Window

Message Priority

Message Encoding Type

Return Receipt

Message Subject

Account

Signature

V-Card

File Attachment Window:

File Attachment Window

Message Window:

Message Window


Scheduler Setup

The Secure Mail System has a built in scheduler that allows you to schedule mail transfer. Their are two types of schedules, by elapsed minutes, and scheduled times. The scheduler setup is found under the Setup Menu Item on the Main Screen.

To setup a schedule, do the following:

1)	Select the type of schedule you wish.

2)	If you selected elapsed minutes, enter the amount of minutes between transfers in the elapsed minute box. If you selected scheduled times, enter the times you wish to transfer mail in 24 hour format in the scheduled time box.

3)	Click the OK button.

The Clear All button will clear all the Scheduled Times.


Remote POP Overview

The Remote POP Feature allows you to manage your messages on the Remote Server. This is useful when you have the Leave On Server Option checked and you want to retrieve a message or clean up old messages that are on the server.

Related Topics:

File Menu

Message Menu

Icon Bar

Message Viewer


Remote POP File Menu

The following items can be found on the File Menu.

Transfer Data:

This will transfer the request you have selected to the server.

Cancel:

This will cancel the Transfer Operation.

Exit:

This will exit the Remote POP Screen.

Related Topics:

Message Menu

Icon Bar


Remote POP Message Menu

The following items can be found on the Message Menu.

Updated Headers:

This will connect to the server and retrieve the available message information from the server and display the results in Message Viewer.

Mark To Retrieve:

This will mark the selected messages to be retrieved from the server and then deleted.

Mark To Retrieve Copy:

This will mark the selected messages to be retrieved from the server but not deleted.

Mark To Delete:

This will mark the selected messages to be delete from the server.

Reset All:

The will rest all selections.

View Headers:

This will display the Message Headers for the selected message.

Related Topics:

File Menu

Icon Bar


Remote POP Icon Bar

The following icons can be found left to right on the Icon Bar.

Updated Headers:

This will connect to the server and retrieve the available message information from the server and display the results in Message Viewer.

Mark To Retrieve:

This will mark the selected messages to be retrieved from the server and then deleted.

Mark To Retrieve Copy:

This will mark the selected messages to be retrieved from the server but not deleted.

Mark To Delete:

This will mark the selected messages to be delete from the server.

Reset All:

The will rest all selections.

View Headers:

This will display the Message Headers for the selected message.

Transfer Data:

This will transfer the request you have selected to the server.

Cancel:

This will cancel the Transfer Operation.

Help:

Displays Remote POP Help File;

Exit:

This will exit the Remote POP Screen.

Related Topics:

File Menu

Message Menu


Remote POP Message Viewer

This are is used to view the messages that are available on the server. You can select messages by clicking on them and the choosing an operation to perform from the Message Menu or by right clicking to bring up the pop up   version of the Message Menu.

If a message has an open envelope next to it, the message has already been retrieved from the server.

Related Topics:

File Menu

Message Menu

Icon Bar

Message Viewer


Message Filtering Overview

The message filtering option of The Secure Mail System allows you to screen messages and act oppon a match. You can auto reply to messages, run programs, save messages to different folders and more.

There are two match criteria’s you can base your match on. Messages Headers, and/or Message Body.  This will allow you the most flexible combination to choose from.

You also can disable or enable each individual message filter by checking or unchecking the Enable This Filter option.

To delete a filter click the Delete button.

See the following topics for more information on each section of the setup screen:

Filter Info. Tab

Search Headers Tab

Search Msg. Body Tab

Reply Message Tab

File Attachments Tab

Run Program Tab

Forward Message Tab


Message Filter Info. Tab

This tab is used to identify the name for this message filter and what to do with the message. The following items can be found on this tab sheet.

Filter Name:

This is the name for this filter. Use a name that identifies the function for this filter like ‘Trash Junk Mail’.

Save Message To Folder:

This is the Message Folder where the message will be sent to after processing. completed. If the folder is a personal folder, it must have been already created in the Folder List Box before it is available in the drop down list.

Add Sender To Address Book:

Check this option if you want to add the senders e-mail address to the selected address book.

Add To Address Book:

This is the address book the e-mail address is added to if the Add Sender To Address Book is checked. The address book must already exists before you can select it.

Save File Attachments:

When this option is checked, it will allow you to automatically save the file attachment into a folder you specify.

Related Topics:

Search Headers Tab

Search Msg. Body Tab

Reply Message Tab

File Attachments Tab

Run Program Tab

Forward Message Tab


Search Headers (Msg. Filtering)

Use this tab to search messages headers for a match. There are 6 predefined headers to choose from. They are FROM, TO, SUBJECT, ORGANIZATION, X-MAILER, and X-ENCODING. If you are familiar with the Internet E-Mail message headers, you can choose any header you wish by typing in the name of the header. The contains string contains the string to look for for a match.

Here is an example: If the Header is FROM and the CONTAINS STRING is ‘tdowe’ and the From Header in the current message contain the address ‘tdowe@anywhere.com’ would be considered a match.

Related Topics:

Filter Info. Tab

Search Msg. Body Tab

Reply Message Tab

File Attachments Tab

Run Program Tab

Forward Message Tab


Search Message Body (Msg. Filtering)

Use this tab to search the messages body for a match. Enter the string to look for for a match.

Here is an example: SEARCH STRING is ‘For Sale’ and the string is found in the current message contain a sentence of ‘1974 Corvette Stingray for sale’ would be considered a match.

Related Topics:

Filter Info. Tab

Search Headers Tab

Reply Message Tab

File Attachments Tab

Run Program Tab

Forward Message Tab


Reply Message (Msg. Filtering)

This tab allows you to enter information for an auto reply. If a filter match should occur, The Secure Mail System will generate a response to the message using a message file. The following items can be found on this tab.

Message File:

This is a text/rtf file that will be used as the message body. Note: Some mailers can not detect alternate file attachment and could cause problems when trying to view your message when a Rich Text File is used.

Message Subject:

The text in this field will be used as the subject line of the message.

Enable Reply:

This will enable the Auto Reply feature of the message filter.

Create/Edit Message File:

This button will allow you to easily edit a reply message using Notepad.

Related Topics:

Filter Info. Tab

Search Headers Tab

Search Msg. Body Tab

File Attachments Tab

Run Program Tab

Forward Message Tab


File Attachments (Msg. Filtering)

If you have enabled Auto Reply, you can attach up to 4 files. Use the Browse buttons to select the files you wish to add to the reply message.

Related Topics:

Filter Info. Tab

Search Headers Tab

Search Msg. Body Tab

Reply Message Tab

File Attachments Tab

Run Program Tab

Forward Message Tab


Forwarding Message Using Message Filtering

This option tab allows you to enter up to four e-mail addresses the filtered message can be sent to. You must specify a complete address in the form of  addressee@domain.com.

Check the Send To Pager if you wish to forward the message to your pager. Use caution when selecting this option as lengthy messages can result in a large number of pager messages. This is only meant for short, quick messages.

Related Topics:

Filter Info. Tab

Search Headers Tab

Search Msg. Body Tab

Reply Message Tab

File Attachments Tab

Run Program Tab


Run Program (Msg. Filtering)

This option tab allows you to specify a program to run when a filter match occurs. The following items are available on this tab.

Program File Name:

This is the location of the program you wish to run.

Parameters:

This is the command line parameters for the above program.

Wait To Finish:

This will halt the execution of The Secure Mail System until the above program has finished execution.

Related Topics:

Filter Info. Tab

Search Headers Tab

Search Msg. Body Tab

Reply Message Tab

File Attachments Tab

Forward Message Tab


Voice Message Overview

A voice message is a message that contains no text, it is audio only. To use this option, you must have a sound card and a microphone.

You can convey much more information and feelings with a voice message then a text message. This aids in getting the point of the message much easier, especially if you are trying to convey a feeling of anger or happiness.

With a Voice Message, you can also load or scan a photo to be sent along with a Voice Message. It is easier to understand a voice message when their is a picture to put with it.

Related Topics:

Voice Message Menu Bar:

File

Audio

Photo

Help

Voice Message Icon Bar:

Icons On Bar

Addressing Information Window:

Address Button

Addressing Type

E-Mail Address

Address Window

Message Priority

Message Encoding Type

Return Receipt

Message Subject

Account

Signature

V-Card

Voice Message Window/Photo Viewer:

Voice Message

Photo Viewer Window


Voice Message File Menu

The following menu items can be found on the file menu.

Send:

This option will send the current Voice Message.

Reply:

This option will reply to the current Voice Message with the option to keep the current Photo.

Forward:

This option will forward the current message to another recipient.

Exit:

This option will exit the Voice Message Screen. If a Voice Message is in preparation, a warning message will appear to ask for confirmation.

Related Topics:

Audio

Photo

Help


Voice Message Audio Menu

The following items can be found on the Audio Menu.

Discard:

This discards the current Voice Message and resets the recorder for a new message.

Load:

Load a previously save recording. This recording must be in CSF format.

Save:

Save the currently recorded message to disk. The saved recording will be in CSF format.

Play:

This will play the currently loaded recording.

Stop:

This will stop playing or stop recording a message.

Record:

This will start recording a message. If a message is loaded or you have stopped recording,  pressing this button will append to the current message.

Related Topics:

File

Photo

Help


Voice Message Photo Menu

The following menu items can be found on this menu.

Discard Image:

This will discard the currently loaded image.

Load Image:

This will allow you to load a image from disk. Supported image formats are (SIF,JPG,GIF, and BMP).

Acquire Image:

If you have a Twain Compliant Scanner attached to your computer, you can directly load an image into the  Photo Viewer. After an image has been acquired, the image will automatically load into the Photo Viewer.

Related Topics:

File

Audio

Help


Voice Message Help Menu

The following items can be found on this menu.

Help Topics:

This will display the table of contents for The Secure Mail System Help File.

Voice Message:

This will display the Voice Message Overview Topic.

Related Topics:

File

Audio

Photo


Voice Message Icon Bar

The following icons can be found on the icon bar from left to right.

Send:

This option will send the current Voice Message.

Reply:

This option will reply to the current Voice Message with the option to keep the current Photo.

Forward:

This option will forward the current message to another recipient.

Help:

This will display the Voice Message Overview Topic.

Exit:

This option will exit the Voice Message Screen. If a Voice Message is in preparation, a warning message will appear to ask for confirmation.


Voice Message Window

The following buttons can be found in the Voice Message Window.

Play:

This will play the currently loaded recording.

Stop:

This will stop playing or stop recording a message.

Record:

This will start recording a message. If a message is loaded or you have stopped recording,  pressing this button will append to the current message.

Discard:

This discards the current Voice Message and resets the recorder for a new message


Voice Message Photo Viewer

The following buttons can be found in the Photo Viewer Window.

Discard Image:

This will discard the currently loaded image.

Load Image:

This will allow you to load a image from disk. Supported image formats are (SIF,JPG,GIF, and BMP).

Acquire Image:

If you have a Twain Compliant Scanner attached to your computer, you can directly load an image into the Photo Viewer. After an image has been acquired, the image will automatically load into the Photo Viewer.


Account Setup

The Account Setup screen is used to setup your information about your Internet Service Provider. If you have more the one account, specify them here. The following options are available here.

Note: be sure to select a default account, otherwise you will not be able to send mail until this is done.

New:

Selecting this option will allow you to setup a new account.

Edit:

Selecting this option will allow you to edit the selected account.

Delete:

This option will delete the selected Account.

Done:

This option will exit the Account Setup Menu.

Related Topics:

Identity

Network

Provider

Defaults


Signature Setup

Use the signature setup screen to define your signatures that you will use to tag the end of your messages.

Signature List:

The signature list contains a list of signature that you have created.

Description:

This is a descriptive name for the signature.

Signature Box:

Use the signature box to create the signature.

New:

Select this option to create a new signature.

Delete:

This will delete the selected signature.

Apply:

This will apply changes that you have made to a selected signature.

Exit:

This will exit the Signature Setup Screen.


V-Card Setup

Use this screen to setup you v-card information. A v-card is a virtual business card that can be sent along with a message. This is an easy way to complete information on how to contact you, should it be necessary.

New:

Selecting this option will allow you to setup a new V-Card.

Edit:

Selecting this option will allow you to edit the selected V-Card.

Delete:

This option will delete the selected V-Card.

Done:

This option will exit the V-Card Setup Menu.

Related Topics:

Personal

Home

Business

Notes

PGP ID


V-Card Personal Settings

 The  Personal Tab of your V-Card, specifies your personal information such as your name and E-Mail Address.

Note: You must specify an e-mail Address.

Related Topics:

Home

Business

Notes

PGP ID


V-Card Home Settings

 The  Home Tab of your V-Card, specifies how someone might contact you at home, or your personal web site. This tab is self-explanatory.

Related Topics:

Personal

Business

Notes

PGP ID


V-Card Business Settings

 The  Business Tab of your V-Card, specifies how someone might contact you at your place of business, or your business web site. This tab is self-explanatory.

Related Topics:

Personal

Home

Notes

PGP ID


V-Card Notes Settings

 The  Notes Tab of your V-Card, allows you to enter notes about your self that might be relevant information that needs to be passed on, for example, times and days you might not be available.

Related Topics:

Personal

Home

Business

PGP ID


V-Card PGP ID Settings

 The  PGP ID Tab of your V-Card, allows for you to send your PGP Public key along with your V-Card Information. This will allow the recipient to send you encrypted mail. You must setup PGP before this option will  be available.

Use the Select Button to Select which public key you wish to add.

Related Topics:

Personal

Home

Business

Notes


Default Settings

Default Account Settings

 The default account settings tab allows you to specify default mail setting for this account. The following default settings are available:

Signature:

This option allows you to select a default Signature from a drop down list that you wish to use for this account. To create a new signature, select the New Button next to the signature box. For more information on creating signatures, see Signature Setup.

V-Card:

This option allows you to select a default V-Card from a drop down list that you wish to use for this account. To create a new V-Card, select the New Button next to the V-Card box. For more information on creating C-Cards, see V-Card Setup.


Composition Format Menu

This menu is used for message formatting. This is helpful in creating professional looking messages. The following options are available from this menu.

Font:

This menu item will display the font dialog box. From this dialog box you can change many option that will effect on how the text in your message looks. You can change only some text by highlighting the text you want to change. The following option can be found on the dialog.

Font:

This option allows you to change the font. You can view what the font looks like in the sample window.

Font Style:

This option allows you to change the style of the font.

Size:

This option allows you to change the size of the font.

Effects:

This options allows you to change the way the text looks, you can change the color of the text, add underlining, and strikeout.

Script:

This changes the way a cursive font looks.

Sample Window:

As you change font settings, you can view what the result looks like in the sample window.

NOTE: The Apply Button will apply the changes to the entire message where the OK Button will only apply the changes to the selected text or from the current cursor position.

Alignment:

This option allows you to change the alignment of the text. The following three option are available.

Left:

This will align the text to the left margin.

Center:

This option will center the text between the Left & Right Margins.

Right:

This option will align the text to the right margin.

Bullet Style:

This option turns on and off Bullet Style listing. This will place a bullet on each new line.

Paragraph:

This option will display the Paragraph Dialog Box. This dialog box allows for you to be able to change the paragraph margins. Set the margins by entering the amount of pixels you want indent. You can also change the Alignment of the paragraph, see Alignment above.

Tabs:

This option will display the Tab Stop Dialog Box. This dialog box allows you to enter tab stop positions. Enter the tab position in pixels then press enter. This will add the tab stop to the list. If you want to clear all tab stops, press the Clear All Button.

Related Topics:

Message Menu


Personal Address Information

Address Options Tab

Use this tab to choose mailing options for this contact. The following items can be found on this tab.

Account:

Select the default e-mail account to use when this contact is selected. See Account Setup for account setup options.

Signature:

Select the default signature to use when this contact is selected. See Signature Setup for setup options.

V-Card:

Select the default V-Card to use when this contact is selected. See V-Card Setup for account setup options.

Plain Text:

Check this option to send pain text message to recipient. If the recipient has RTF support, leave this unchecked, you will then be able to send RTF message to the recipient.

Return Receipt:

This will automatically check the return receipt option when you compose a new e-mail message for this e-mail addressee. The Return Receipt option allows you to get a message from the mailer demon stating that the message has arrived at the destination mail box. This does not mean that the recipient has read the message it just indicates that it is in his mailbox waiting for delivery.

Priority Option:

This will automatically set the priority level option when you compose a new e-mail message for this addressee. The message priority is used for an indicator to indicate how important the message is. This will not deliver the message any faster, it just gives you a visual indication that the message should not be ignored or that the message is not important at all. The Secure Mail System would display a burning envelope or a burning lock to indicate that the message has a high priority. This option only works with mailers that have this feature.

Related Topics:

Address Listing Screen

Details

PGP Information

Picture ID


Picture ID

Address Book Picture ID Tab

This tab allows you to add a picture of the addressee to your address book. Use the Set Picture Button to select a Bit Map file to use. Use the Delete Picture Button to remove the file from the address book.

Related Topics:

Address Listing Screen

Details

PGP Information

Mail Options


Backing Up Data Files

This option can be found on the File Menu on the Main Screen. This option will allow you to save all your setup information in the event of a system failure.

To create backup files do the following:

1?	You must first select the location and file name of the backup file. Use the BROWSE button to do this.

2?	Select the data types you wish to save in the options boxes.

3?	Click on the Backup button.

Related Topics:

Restore Data Files


Restoring Data Files

This option can be found on the File Menu on the Main Screen. This option will allow you to restore all your setup information in the event of a system failure.

To restore the data files do the following.

1?	You must have already created a backup file.

2?	Select the backup file to use using the Browse button.

3?	If not restoring to the original locations, select the destination directory for the selected files. If restoring to original locations, you must select the drive that The Secure Mail System or PGP files will be stored.

4?	If not restoring to the original locations, you must restore PGP files and Secure Mail files in two different restore operations in their respective directories. Otherwise all files will be restored to the current selected directory.

5?	Selecting the Overwrite option will restore and overwrite any existing files, if not selected, only missing files will be restored.

6?	Selecting the Original Location option will restore the files in the same location as when the backup file was created.

7?	Select the Restore button to start the restore procedure.

Related Topics:

Backup Data Files


Network Settings

This area is used to define network options. If this area is not setup correctly, you will not be able to connect to a network and send and retrieve your e-mail messages.

Network To Dial:

If you are using an Alternate Provider you must select the network from the drop down list you would like to connect to. If the list is empty, you have not setup Dialup Networking for your Service Provider. The Secure Mail System uses your Dialup networking to make the phone call and hook up to your Internet e-mail provider.

Network Password:

This is the password that is required to access the above network. Your service provider may have assigned this. For examples if your alternate provider is MSN then type in the password that they gave you here.

Use Local Network:

If you are connected to a Local Area Network that has access to the Internet, check this 	option. This will disable the dialer and access the POP3/SMTP server through the LAN.

Generally if your are using a computer at an organization that has a group of computers connected to a server with a computer guy that keeps the whole thing running you’re probably on a LAN. Best to talk to this person on the settings to use so you can send and receive e-mail.

Leave On Server:

This allows you to keep your messages on the server after retrieving your messages. This is useful if you get mail with multiple computer or just to keep for backup. The number of day’s option allows you to set the number of day the messages will remain on the server before they are deleted. If the number of days is set to zero, then the messages will remain on the server until you manually remove them using the Remote POP Option.

Auto Radial:

Enabling this function will cause The Secure Mail System to radial your Internet e-mail provider in event that the line is busy. To enable auto radial you have to enter a number greater then zero in the ‘radial attempts’ field.  A number entered into the ‘radial wait time’ will be in seconds between the radial attempts.

See Setup for other setup options.


Icon Bar

Main Icon Bar

The Icon bar is where you can find quick access to commonly used menu functions. Small hints will appear if you let the mouse rest on the icon for a moment, this will give you information on what that icon will do when you click on it. Below is a list of functions that you can find on the Icon Bar listed from left to right.

Address Book 	Brings up your address book

Run PGP Manager	Displays all you public keys in your key ring

Compose Mail Message	Brings up the message editor

Compose Voice Message	Brings up the voice message editor

Read Mail	Brings up the selected message for reading

Delete Selected Message 	Deletes a selected message

Mark Read	Marks the selected messages as read

Mark Unread	Marks the selected messages as unread

New Folder	Create a new personal folder

Delete Selected Folder	 	Deletes the selected personal folder

Call Server	Calls the Mail Server and transfers mail

Send Outgoing Only	Calls the Mail Server and transfers outgoing mail only

Retrieve Incoming Only	Calls the Mail Server and transfers incoming mail only

Cancel Server Call	Cancels the call to the Mail Server

Printer Setup	Setup the printer

Help	Brings up the help topic menu

Exit	Terminates the application


Address Book Overview

The address book contains information about individuals that you converse with a lot. Their are two sections to the Address Book, the Address Listing Screen and Address Data Screen.

The Address Listing Screen is a list of addressees that are currently in the Address Book. This screen is also used when selecting recipients for an e-mail message when the Address Button is selected during mail composition.

Related Topics:

Address Listing Screen

Address Button

General Information

Details

PGP Information

Mail Options

Picture ID


Address Listing Screen

This screen displays a list of category lists that are currently in your Address Book and a list of address will be displayed from the current selected category. From this screen you can create New Entries or Edit the selected entries. The following areas can be found on the Address Listing Screen.

Main Menu:

File:

Import:

This option allows you to import from a Netscape 3.0 address book or HTML file. To import an address file from Netscape, go to your Netscape\Navigator folder and select the address.htm file.

Exit:

Exits the address book.

Category Books:

New Category:

This option allows you to add a new category to your address book.

Rename Selected Category:

This option allows you to rename the selected category to a new name.

Delete Selected Category:

This option allows you to delete the selected category.

Category Window:

This window displays the categories you have available. Use the Category Menu item to Add, Delete or Rename your categories.

Address Listing Window:

This window displays information on each addressee you have currently in Address Book. There are three sections to this window, which are listed below.

Full Name:

This is the person’s full name. There is an icon in front of the full name, which specifies if this addressee has PGP Information stored in the address book. If the address has PGP Information available, then there will be a Lock icon in front of the e-mail address, otherwise there will be an envelope.

Company Name:

This is the company name for which the person may work.

Business Phone:

This is the person’s work or business contact phone number.

Home Phone:

This is the person’s work or business contact phone number.

TO Button:

This button becomes available if you selected the Address Button during mail composition. This button enters the selected address as a recipient of the e-mail message.

NOTE: Double clicking on the e-mail name will have the same result as selecting the TO Button.

CC Button:

This button becomes available if you selected the Address Button during mail composition. This button enters the selected address as a carbon copy recipient of the e-mail message. The names listed with the CC selection will be included in the outgoing message.

BCC Button:

This button becomes available if you selected the Address Button during mail composition. This button enters the selected address as a blind carbon copy recipient of the e-mail message.  Blind copy recipients are almost the same as Carbon copy recipients (CC), the only difference is the names listed in BCC will not appear in the message.  Hence if the message corresponds to the message which has been received, BCC list will be empty.

Edit Button:

Selecting this button will allow you to edit the information of the selected addressee.

New Button:

Selecting this button will allow you to add a new addressee into your Address Book.

Icon Bar:

The following icons can be found on the Icon Bar.

Delete Button:

This will delete the selected contacts from the address book.

Send Message:

This will prepare a message to be sent to the selected user.

Call:

This will place a call to the selected contact. This option requires the phone dialer to be installed.

Web Site:

If you have entered a web address for a contact, you can directly go to the web site by selecting this button.

Print:

Selecting this button will print the selected contact.


Message Window

The Message Window is where the message body is displayed. Here you read or compose your message. The message window is Rich Text compatible and there for allows you to be able to change fonts and many other formatting options. See the Format Menu for more information on message format. You can pop up the Format Menu by clicking the right mouse button while the mouse pointer is inside the Message Window. You also have the option to load a RTF or TXT document by selecting Load Document from the Message Menu. Use the Edit Menu to access the message editing options.


Personal Address Information

Address Book General Information Tab

This tab is used for entering general information about a contact. Here you can enter detailed information about a specific contact, including notes.

Related Topics:

Address Listing Screen

Details

PGP Information

Mail Options

Picture ID


Personal Address Information

Address Book Details Tab

Use this tab to enter detailed information about a contact. Most of this tab is self-explanatory. You can also load a business card into the detail information tab. If you have a Twain compliant scanner, you can directly scan the image into the contact form.

Related Topics:

Address Listing Screen

PGP Information

Mail Options

Picture ID


Address Book PGP Information

The information on this tab is only available if PGP has been installed. The data that is entered in this tab is used to look up the recipient PGP User ID when you encrypt a message or file to this addressee. This avoids you having to manually select the PGP User ID every time you encrypt a message to this addressee. Another good reason to enter the addressees public key information in this tab is if the addressees PGP User ID is not easily identifiable, such as if the case were to be if the ID were all numbers or a handle that does not mach his e-mail name or address. There are two field on this tab and they are listed below.

User ID:

This is the addressee PGP User ID. To enter the User ID, you must have already added his/her PGP key to your public key ring. Then press the select button. This will bring up the key selection dialog box. Select the appropriate key for this addressee.

Signature Fingerprint:

This field contains the addressee’s key fingerprint that can be used to verify a key over the phone. To enter the Key Fingerprint, you must have already added his/her PGP key to your public key ring. Then press the select button. This will bring up the key selection dialog box. Select the appropriate key for this addressee, you will then be asked if you would like to retrieve the key finger print also, select YES.

Related Topics:

Address Listing Screen

Details

Mail Options

Picture ID