DURING WORLD WAR II, the Germans mounted a war effort extending over an expanse so vast that it could not be coordinated except via radio. Theoretically this made their communications vulnerable to interception, but the Germans placed their faith in Enigma, a machine capable of generating a code so complex that they considered it unbreakable. Yet the British did manage to break it. The story of how they did so is the subject of The Imitation Game, the 2014 film directed by Morten Tyldum, starring Benedict Cumberbatch as its main character, the brilliant mathematician Alan Turing.
In the film, Turing is at the heart of a quintet of cryptographers recruited by the recently created MI6, Great Britain’s Secret Intelligence Service. Each day the team has 18 hours in which to decrypt German messages before the Germans change their Enigma settings at midnight. The other four team members earnestly try to break the code via human ingenuity, but Turing does not try. Instead he spends his days building a protocomputer that can grind through all possible Enigma settings within minutes: Turing believes that it takes a machine to defeat a machine.
The film portrays Turing as insufferably arrogant, the consequence of his incapacity to read basic social cues. He can’t even understand a joke. His colleagues detest him, until they realize that Turing’s construction of the protocomputer is the only way to defeat Enigma. Once the code is broken, Turing, thanks to his inability to empathize, is the first to realize that this development must be hidden not only from the enemy, but even from most of the Allied high command: otherwise the Germans will realize that something is amiss and reprogram Enigma to make it even more difficult to break.
Film critics widely praised The Imitation Game when it was first released. The film received eight Academy Award nominations—including a Best Actor nod for Cumberbatch—and won for Best Adapted Screenplay. But the movie is as much about Turing personally as it is about learning the secret of Enigma. It addresses his life both before and after the war, particularly his homosexuality, which in the Great Britain of that day was a criminal offense.
This focus on Turing leads to the deliberate distortion of a number of historical facts within the film. In reality, for example, the breaking of the Enigma code involved dozens of individuals, not just a handful. And Turing’s contribution was not to invent a new machine from scratch, but to improve upon an existing machine by designing one that broke the Enigma code faster. Turing also had help from another mathematician, Gordon Welchman, who is not even mentioned in the film.
Nevertheless, as a professor who teaches a course on World War II, I do not hesitate to show The Imitation Game in class, because it contains much that is accurate. For starters, there’s the Enigma machine itself, and the difficulty of cracking its code. A compelling scene early in the film shows a German observation plane spotting a convoy; the use of an Enigma machine to communicate the convoy’s position; the decryption of its message in Berlin; and its relay to a U-boat wolf pack massing for a devastating attack. In voiceover, Turing explains the challenge facing the British. “The game,” he says, “was quite a simple one. Every single German message, every surprise attack, every bombing run, every imminent U-boat assault…they were all floating through the air. Radio signals that…any schoolboy with an AM [radio] kit could intercept. The trick was that they were encrypted. There were 159 million million million possible Enigma settings. All we had to do was try each one.” But, he continues, if the British had 10 cryptographers checking one setting a minute for 24 hours every day, seven days every week, it would take 20 million years to check them all. “To stop an enemy attack,” Turing concludes, “we would have to check 20 million years’ worth of settings in 20 minutes.”
It takes about a minute for this sequence to play out, but it makes vividly clear the difficulty of breaking the Enigma code and the urgency of doing so. The Imitation Game also depicts the basic techniques utilized, and shows why the British couldn’t just use human intelligence to counter each German move. But more than anything, the film is welcome in my class because human beings learn best through storytelling, and it explains the challenge of decoding Enigma in a way that a textbook or lecture could not. The film gives my students not just information, but an indispensable emotional understanding of the human drama. ✯