Armies and civilian secret-keepers alike quickly took up polyalphabetic ciphers as a much more secure way to communicate. To code them quickly, senders used tools like the cipher disk in the image ...

He explores polyalphabetic substitution ciphers, transposition ciphers, including one developed by the Spartans, connections between ciphers and computer encryption, stream ciphers, ciphers involving ...

Far more sophisticated is the polyalphabetic cipher, which was first defined by Leon Battista Alberti in about 1467, although some argue it may have been developed by the Arab cryptologist Al ...

Object Details Author Churchhouse, R. F Contents 1. Introduction -- 2. From Julius Caesar to simple substitution -- 3. Polyalphabetic systems -- 4. Jigsaw ciphers -- 5. Two-letter ciphers -- 6. Codes ...

Last time I talked about complex polyalphabetic ciphers--techniques of encoding information that make it nearly impossible to reveal the message without access to a secret key. Because the ...