Secret Code Book

An introduction to substitution ciphers. Begin Reading for Free >> Introduction Chapter 1: The Rot-N Cipher Chapter 2: Englis...

Introduction Throughout history, there has been an ongoing effort to ensure the secrecy of communications. For every innovation in desig...

The Rot-N Cipher  A substitution cipher is a method used to encode a message by replacing each letter with a symbol, drawing, number or a...

English Rot13 Cipher  The English language consists of 26 letters (a-z) which is exactly divisible by 13. This allows for the equal assoc...

Cracking the Code  When using ciphers, it is always important to understand how an adversary might decipher, or “crack”, your code. Knowi...