Introduction Overview

This module introduces Chapter 1 of the CryptoClub Cipher Handbook, Caesar Ciphers. The Caesar Cipher is one of the earliest ciphers used. It is named for Julius Caesar who used a cipher that shifted the alphabet by 3 letters whenever he wanted to communicate secret information. Later the name was applied to any cipher that shifts the alphabet. While today it is insecure for encrypting confidential messages, at the time of Julius Caesar it was innovative and useful for keeping military secrets.