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 ...

To decrypt the message, the process is reversed. Caesar ciphers are often shown using a Caesar cipher wheel diagram, to illustrate that when the end of the alphabet is reached it goes around again.

Cryptography is nearly as old as human language. Many civilizations felt the need to conceal their messages using more or less sophisticated encryption methods, as demonstrated by some documentary ...