Caesar Cipher
The Caesar cipher is a code Julius Caesar invented 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. It is probably one of the most simple codes ever. It is 3 letters back so A would be X. The Rot Cipher is almost the same as the Caesar Cipher.
The action of a Caesar Cipher is to replace each plaintext letter with a different one a fixed number of places down the alphabet. The cipher illustrated here uses a left shift of three,so that each occurrence of E on the plaintext becomes B in the ciphertext.
The transformation can be represented by aligning two alphabets; the cipher alphabet is the Alphabet rotated left or right by some number of positions.
Plain: ABCDEFGHIJKLMNOPQRSTUVWXYZ
Cipher: XYZABCDEFGHIJKLMNOPQRSTUVW
A cipher text using a left rotation of three places, equivalent to a right shift of 23 (the shift parameter is used as the key).
When encrypting,a person looks up each letter of the message in the "plain" line and writes down the corresponding letter in the "cipher" line.
