The Imitation Game Christopher soon dies from tuberculosis. When Britain declares war on Germany in 1939, Turing travels to Bletchley Park. Under the direction of Commander Alastair Denniston, he joins the cryptography team of Hugh Alexander, John Cairncross, Peter Hilton, Keith Furman and Charles Richards. The team are trying to decrypt the Enigma machine, which the Nazis use to send coded messages. Turing is difficult to work with, and considers his colleagues inferior; he works alone to design a machine to decipher Enigma. After Denniston refuses to fund construction of the machine, Turing writes to Prime Minister Winston Churchill, who puts Turing in
Cryptanalysis of the Enigma in World War II. The strength of the security of the ciphers that were produced by the Enigma machine was a product of the large numbers associated with the scrambling process. However, the way that Enigma was used by the Germans meant that, if the settings for one day (or whatever period was represented by each row of the setting sheet) were established, the rest of the messages for that network on that day could quickly be deciphered. The security of Enigma ciphers did have fundamental weaknesses that proved helpful to cryptanalysts. Enigma featured the major operational convenience of being