German military messages enciphered on the Enigma machine were first broken by the Polish Cipher Bureau, beginning in December 1932. This success was a result of efforts by three Polish cryptologists, Marian Rejewski, Jerzy Różycki and Henryk Zygalski, working for Polish military intelligence. Rejewski reverse engineered the device, using theoretical mathematics and material supplied by French military intelligence. Subsequently the three mathematicians designed mechanical devices for breaking Enigma ciphers, including thecryptologic bomb. From 1938 onwards, additional complexity was repeatedly added to the Enigma machines, making decryption more difficult and requiring larger numbers of equipment and personnel–more than the Poles could readily produce.On 25 July 1939, in Warsaw, the Poles initiated French and British military intelligence representatives into their Enigma-decryption techniques and equipment, including Zygalski sheets and the cryptologic bomb, and promised each delegation a Polish-reconstructed Enigma. The demonstration represented a vital basis for the later British continuation and effort.During the war, British cryptologists decrypted a vast number of messages enciphered on Enigma. The intelligence gleaned from this source, codenamed “Ultra” by the British, was a substantial aid to the Allied war effort
The Imitation Game is a movie about Alan Turing who joins to the cryptography team of Hugh Alexander , John Cairncross, Peter Hilton Keith Furman and Charles Richards and is trying to decrypt the Nazi Enigma machine.Then he is naming the Enigma-breaking machine “Christopher” after Turing’s childhood friend. In actuality, this electromechanical machine was called ‘Victory’. Victory was a British Bombe machine, which drew a spiritual legacy from a design by the Polish Cryptanalyst Marian Rejewski. Rejewski designed a machine in 1938 called bomba kryptologiczna which exploited a particular, but temporary, weakness in German operating procedures. A new machine with a different strategy was designed by Turing (with a key contribution from mathematician Gordon Welchman, unmentioned in the film) in 1940.