WARNING! : UNEDITED!
The Caesar shift cipher, named because it was used by Julius Caesar himself, Juluis invented it when he mailed letters. He invented it so if his messenger was robbed of that letter and the robber wouldn't be able to read it.Its actually 26 different ciphers, one for each letter of the alphabet. ROT1 is just one of these ciphers. A person only needs to be told which Caesar cipher was used in order to decipher a message. If the G cipher is used, then A becomes G, B becomes H, C becomes I, and so on through the alphabet. If the Y cipher is used, then A becomes Y, B becomes Z, C becomes A, and so on. This cipher is the basis for many more complex ciphers, but on its own does not allow great protection of a secret message, as checking 26 different cipher keys does not take a relatively great amount of time.
PINKY_DUST
