Labels:text | font | black and white | paper | document OCR: words into numbers and then scrambling the digits carried the key would be too expensive. Hellman mathematically. What dawned on Hellman and and Diffie remedied this problem by letting each Diffie was that a class of extraordinarily difficult user place his encryption key in a public file, at the mathematical problems, known as one-way func- same time keeping the decoding procedure a secret. tions, acted like their bank machine. A practical Since then Ronald Rivest, an MIT computer- code could be built on them. Users would be able to list their encoding keys in a directory so that anyone science professor, and his colleagues Adi Shamir and Len Adleman have made the code breaker's job could send them a coded message. Yet only they even more difficult by using a new set of one-way would have ...
