Alan Turing worked on enigma (Bletchley Park - 1930-1940)

Alan Turing

Alan Mathison Turing, OBE, FRS (/ˈtjʊərɪŋ/ TEWR-ing; 23 June 1912 – 7 June 1954), was a British mathematician, logician, cryptanalyst, and computer scientist. He was highly influential in the development of computer science, giving a formalisation of the concepts of "algorithm" and "computation" with the Turing machine, which can be considered a model of a general purpose computer.^[3][4] Turing is widely considered to be the father of computer science and artificial intelligence.^[5]

• http://en.wikipedia.org/wiki/Alan Turing