A few years after the publication of his landmark paper, Alan Turing turned his attention to cryptography.  Europe was at war and  Nazi Germany had devised a machine, the Enigma, which was capable of  encrypting  wartime communications.  Turing, with a team of mathematicians recruited by the government,  designed a machine (the Bombe) capable of breaking the German code. For the first time,  a machine had been used to decipher a code. In the post-war years, Turing worked on  the design of a real electronic computer, the Automated Computing Engine (ACE) , the development of a programming language for the ACE, and the concept of artificial intelligence.  

Sadly, Alan Turing's career ended tragically and prematurely. During the 1950's,  homosexuality was a crime in England.  In 1952, Alan Turing was arrested because of his sexual orientation and charged with "gross indecency." Two years later, he was found dead after eating a cyanide laced apple. His death was ruled a suicide.

 Alan Turing's work  is considered the theoretical foundation of modern  computer science. His life is the subject of the book Alan Turing, the Enigma by Alan Hodges  as well as the award winning play, Breaking the Code by Hugh Whitmore.   

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