In cryptography, a Caesar cipher is one of the simplest and most well-known classical 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 further 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 for all single alphabet substitution ciphers, the Caesar cipher is easily broken and in practice offers no communication security.

Read the rest of this article: http://en.wikipedia.org/wiki/Caesar_cipher

_______________________________ Today's selected anniversaries:

467: Anthemius became Emperor of the Western Roman Empire. (http://en.wikipedia.org/wiki/Anthemius)

1633: The formal interrogation of Galileo Galilei by the Inquisition began. (http://en.wikipedia.org/wiki/Galileo_Galilei)

1961: Soviet cosmonaut Yuri Gagarin became the first man to enter outer space. (http://en.wikipedia.org/wiki/Yuri_Gagarin)

1980: Terry Fox dipped his artificial leg in the Atlantic Ocean and began his trans-Canada run towards the Pacific Ocean to raise money for cancer research. (http://en.wikipedia.org/wiki/Terry_Fox)

1981: Columbia, the first space shuttle, was launched for its first flight. (http://en.wikipedia.org/wiki/Space_Shuttle_Columbia)

_____________________ Wikiquote of the day:

"A living body is not merely an integration of limbs and flesh but it is the abode of the soul which potentially has perfect perception, perfect knowledge, perfect power, and perfect bliss." -- Mahavira (http://en.wikiquote.org/wiki/Mahavira)