Ciphers were first used by the Romans hundreds of years ago. Julius Caesar created one of the first Ciphers to make sure messages to his troops were not intercepted. The Caesar Cipher is a Simple Substitution Cipher where each letter is simply replaced by the letter three spaces after it in the alphabet. Over the years many other more complicated ciphers such as Affine, Vigenere, and Transposition ciphers were created. For more detailed information about historical ciphers go to this cipher site.