Alan Turing

Alan Turing was an English mathematician, logician, cryptanalyst and computer scientist. He was born in Maida Vale, London, England, and United Kingdom on June 23, 1912. Turing was also a very good inventor especially on computing machinery. An example of his inventions began with his momentous paper "On Computable Numbers, with an Application to the Entscheidungs problem", Turing reformulated Kurt Gödel's 1931 results on the limits of proof and computation, replacing Gödel's arithmetic-based language with what became known as Turing machine (http://en.wikipedia.org/wiki/Alan_Turing#Childhood_and_youth). In addition, in 1937, Alan Turing described the idea of his Turing machine as a mathematical tool that could absolutely recognize undecidable propositions. Alan Turing had been identified, at Cambridge, as a likely candidate for code breaking and he came to the Government Codes & Ciphers School to try and intercept German signals from a machine called the enigma machine. Alan Turing had been thinking for some time of ways to attack Enigma so his main ideas was based around what is now called "known plain text" (KPA) and what became known in Bletchley Park as a "crib." KPA is an attack model for cryptanalysis where the attacker has samples of the plaintext, a crib, and its encrypted version (ciphertext). But when a captured German revealed under interrogation that Enigma operators had been instructed to encode numbers by spelling them out, Alan Turing reviewed decrypted messages, and determined that the word “eins” ("1") appeared in 90% of the messages. He automated the crib process, creating the Eins Catalogue, which assumed that “eins” was encoded at all positions in the plaintext. The catalogue included every possible position of the various rotors, starting positions, and key settings of the Enigma (http://en.wikipedia.org/wiki/Known-plaintext_attack).

In conclusion was an exceptional man to society no only for creating his universal Turing...