“The Imitation Game” (2014)

The work

The film was directed by Morten Tyldum from a screenplay by Graham Moore, based on Andrew Hodges’s biography of Turing. Turing is played by Benedict Cumberbatch; the cast also includes Keira Knightley, Matthew Goode, Charles Dance and Mark Strong. The film runs for 114 minutes.¹

The real case

Alan Turing joined GC&CS at Bletchley Park in September 1939 and led the work on German naval Enigma in Hut 8.^4,5

The starting point was the work of the Polish Cipher Bureau. On 25–26 July 1939 at Pyry near Warsaw the Poles handed their methods and copies of Enigma to the British and French; according to GCHQ this changed the British approach to breaking the machine, and Turing’s discussions with Marian Rejewski in Paris in January 1940 formed the basis for the concept of the first British Bombe (see Breaking Enigma).⁶

The Foreign Office historian Gill Bennett writes that the Polish results shortened the British attack on Enigma by at least a year.⁷

What is accurate

David Hatch, reviewing the film in the CIA journal ‘Studies in Intelligence’ (2015), writes that it pays tribute to Turing, who did make important contributions at Bletchley Park towards exploiting German cryptosystems. He also praises the writing and the performances, Cumberbatch’s in particular.²

What was added or changed

According to Hatch, the film makes Turing the centre of all the successful cryptanalytic activity at Bletchley Park. In reality Turing designed the Bombe, but it was built elsewhere, and Gordon Welchman made it faster and more efficient.²

Alastair Denniston, head of GC&CS, appears in the film as a military martinet who opposes Turing. Hatch points out that Denniston was replaced as director early in the war for management reasons, not because of any quarrel with Turing. Hugh Alexander, a bragging womaniser on screen, was by the outbreak of war already married and a good family man.²

Also untrue is the plot line in which Turing’s team itself decides which decrypts reach the military. Hatch stresses that no one’s life was sacrificed to protect the Ultra secret.²

The subplot of a Soviet spy at Bletchley Park exposed by a ‘Beale cipher’ is, according to Hatch, misconceived: the ‘Beale cipher’ is a specific encrypted message from Virginia, not a kind of cipher. A newspaper in the film calls Turing a Cambridge professor, whereas he was a professor at the University of Manchester.²

The Polish contribution in the film

According to media and secondary accounts · not confirmed by official sourcesTony Comer, the GCHQ historian, told the Polish Press Agency (PAP) in 2016 that the film tells the story of Turing and his team, mentioning the Polish part in the process only to a very small degree, and perpetuates a mythologised version of events. He himself compares the breaking of Enigma to a relay race of Polish, French and British cryptologists in which the Poles ran the first lap.³

According to media and secondary accounts · not confirmed by official sourcesA reviewer for RMF FM counted in 2015 that the word ‘Poland’ is spoken in the film four or five times, including in captions about where events take place, and that a viewer unfamiliar with the history would not learn of the Polish contribution from the film.⁸