This Caesar Cipher wheel project will encipher or decipher messages where the ciphering alphabet is shifted without changing the order of the letters. Spaces, numbers, and special characters remain unencrypted, so it may be better to spell numbers out to increase security. The Roman commander Julius Caesar (100 BCE – 44 BCE) used a very simple cipher for secret communication during the Gallic Wars. He substituted each letter of the Greek alphabet with a letter three positions further along. As he and his legions crossed through modern France and Germany, if his messengers were intercepted by the Celtic tribes he was fighting against, even the Celts that had learned Latin or Greek in their dealings with Roman traders would be faced with an unfamiliar scrambled alphabet. Later, military communications experts referred to any cipher that used this “shift” concept for the creation of a cipher message as a Caesar cipher. Of all the substitution ciphers, the Caesar cipher is also the simplest to solve, since there are only 25 possible combinations that hide the original message. For Caesar, this was not a problem, as the messages he was sending usually included time-critical information about the movement of troops--the message only had to be secure long enough for him to get his legions on the march. Balancing security with ease of use to meet the needs of the message made this an effective tool for many years.
