Introduction If you need to send a secret message to a friend, how could you prevent other people from reading it? One way is to encrypt the message—that is, use a secret code that only you and your ...

Introduction to ciphers and substitution. Alice and Bob and Carl and Julius: terminology and Caesar Cipher ; The key to the matter: generalizing the Caesar Cipher ; Multiplicative ciphers ; Affine ...

The arena of creating secure environments in the hardware and software industries is somewhat shrouded in mystery and misunderstanding. Certainly, some types of ciphers are relatively straightforward ...

1. Introduction -- 2. From Julius Caesar to simple substitution -- 3. Polyalphabetic systems -- 4. Jigsaw ciphers -- 5. Two-letter ciphers -- 6. Codes -- 7. Ciphers for spies -- 8. Producing random ...

NOVA scienceNOW's "Can Science Stop Crime" introduced you to Tadayoshi Kohno, a University of Washington computer scientist who's made it his mission to take over networked machines, identifying ...

Until the twentieth century, cryptography—the scrambling of messages to make them obscure to everybody except an intended recipient—was a relatively straightforward business, based on principles used ...