Moment By Moment - A personal diary and updates

In cryptography, a Caesar cipher, also known as a Caesar's cipher, the shift cipher, Caesar's code or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. For example, with a shift of 3, A would be replaced by D, B would become E, and so on. The method is named after Julius Caesar, who used it to communicate with his generals. The encryption step performed by a Caesar cipher is often incorporated as part of more complex schemes, such as the Vigenère cipher, and still has modern application in the ROT13 system. As with all single alphabet substitution ciphers, the Caesar cipher is easily broken and in practice offers essentially no communication security. Example:
The transformation can be represented by aligning two alphabets; the cipher alphabet is the plain alphabet rotated left or right by some number of positions. For instance, here is a Caesar cipher using a left rotation of three places (the shift parameter, here 3, is used as the key):

ABCDEFGHIJKLMNOPQRSTUVWXYZ = Plain Alphabet
DEFGHIJKLMNOPQRSTUVWXYZABC = Cypher Alphabet

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. Deciphering is done in reverse.

THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG = Plain text
WKH TXLFN EURZQ IRA MXPSV RYHU WKH ODCB GRJ = Cyphertext

Try this

Some say that Kubric used a 1 shift when he named the computer HAL in his 2001: Space Odyssey.

ABCDEFGHIJKLMNOPQRSTUVWXYZ = Plain Alphabet
BCDEFGHIJKLMNOPQRSTUVWXYZA = Cypher Alphabet

If you work back one letter you get...

IBM!