Black Crawling Systems Archive Release 1.0/Black Crawling Systems Archive Release 1.0 (L0pht Heavy Industries, Inc.)(1997).ISO/blackcrwl/encrypt/ONETIME.ZIP/ONETIME.DOC

Text File | 1993-02-17 | 2KB | 36 lines

***********One-Time Cipher*************   version 1.00 by Jonathan Lasser

This is a one-time cipher.  The formula used is sin(x^3).

The program asks if you are encoding or decoding the data.  Type E or D.

The program asks you for the PLAINTEXT file name.  This is the english (or
binary) data when it is not coded.

The program asks you for the CIPHERTEXT file name.  This is the encrypted data.

The program asks you for the starting value of X.  This is one of the two
parameters that are special.

The program asks you for the step value of X.  This is the other special para-
meter.

To decipher a message, you need both the START and STEP values.  If someone
else finds these values, then the data can be read.  You must find a way to
decide these values so that nobody else can figure them out.  You might want
to use things like the file date/size, or something.  They can be any real
number.

If you don't know what a one-time cipher is, or why it is secure, find a good
book on ciphers or security and find out.  This is not the place for a de-
scription.  You don't need to understand what makes this secure, but it does
help.

I've tried about 1/2 meg of sample data, including executable files and text
files.  There has not been one single error in encryption/decryption in that
time.  However, I can't guarantee that there aren't any bugs.  If you put the
wrong filenames in the wrong places, you may overwrite your source data.  The
program is very basic and doesn't check.

If you have any questions, I can be reached on the Brentwood BBS [phone].