Alan Turing: The Enigma: The Book That Inspired the Film "The Imitation Game"
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A NEW YORK TIMES BESTSELLER
The official book behind the Academy Award-winning film The Imitation Game, starring Benedict Cumberbatch and Keira Knightley
It is only a slight exaggeration to say that the British mathematician Alan Turing (1912-1954) saved the Allies from the Nazis, invented the computer and artificial intelligence, and anticipated gay liberation by decades--all before his suicide at age forty-one. This New York Times-bestselling biography of the founder of computer science, with a new preface by the author that addresses Turing's royal pardon in 2013, is the definitive account of an extraordinary mind and life.
Capturing both the inner and outer drama of Turing's life, Andrew Hodges tells how Turing's revolutionary idea of 1936--the concept of a universal machine--laid the foundation for the modern computer and how Turing brought the idea to practical realization in 1945 with his electronic design. The book also tells how this work was directly related to Turing's leading role in breaking the German Enigma ciphers during World War II, a scientific triumph that was critical to Allied victory in the Atlantic. At the same time, this is the tragic account of a man who, despite his wartime service, was eventually arrested, stripped of his security clearance, and forced to undergo a humiliating treatment program--all for trying to live honestly in a society that defined homosexuality as a crime.
The inspiration for a major motion picture starring Benedict Cumberbatch and Keira Knightley, Alan Turing: The Enigma is a gripping story of mathematics, computers, cryptography, and homosexual persecution.
in creating a defence against imagined spying and treachery. The cumbersome disguise succeeded in confusing their own officers: On one occasion we successfully solved a disguised grid reference and diverted a convoy clear of a waiting patrol line, only to find that the C.O. of one of the U-boats involved had not been as clever as we had and had misinterpreted the disguised grid reference given in his orders and blundered into the convoy in consequence. In November 1941 the system was made
to cryptographers that the Baudot-Murray code could be used as the basis for an ‘adding on’ type of cipher. The principle was dignified with the name of the American inventor G.S. Vernam. In fact a Vernam cipher was based on the simplest possible kind of adding, since ‘modular’ addition with binary digits would use nothing but the rules shown in the figure. The Relay Race In other words, a plain-text teleprinter tape could be ‘added’ to a key teleprinter tape, according to the rule that a
and responsible statements as ‘gibberish’ was not the most tactful policy. Darwin and Hartree were, in fact, echoing the comment by Ada, Countess of Lovelace, who wrote an account38 of Babbage’s planned Analytical Engine in 1842, and claimed that ‘The Analytical Engine has no pretensions whatever to originate anything. It can do whatever we know how to order it to perform.’ At one level, this assertion certainly had to be urged against the very naive view that a machine doing long and elaborate
whether Euclidean geometry was, regarded as an abstract exercise, a complete and consistent whole. It was not clear that Euclid’s axioms really did define a complete theory of geometry. It might be that some extra assumption was being smuggled into proofs, because of intuitive, implicit ideas about points and lines. From the modern point of view it was necessary to abstract the logical relationships of points and lines, to formulate them in terms of purely symbolic rules, to forget about their
ideas in which Bernard Shaw himself might have found a plot: You have often asked me about possible applications of various branches of mathematics. I have just discovered a possible application of the kind of thing I am working on at present. It answers the question ‘What is the most general kind of code or cipher possible’, and at the same time (rather naturally) enables me to construct a lot of particular and interesting codes. One of them is pretty well impossible to decode without the