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 ...

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 ...

Before we move into the meat of this article, let’s define a couple terms related to cryptography. The syllable crypt may make you think of tombs, but it comes from a Greek word that means “hidden” or ...

Introduction The Shorter Oxford English Dictionary lists the 5th meaning of the word cipher as, “A secret manner of writing by any of various methods, intelligible only to those possessing the key ...