Ordinarily the life of a mathematician isn’t ideal fodder for a major Hollywood movie. But when that mathematician is Alan Turing — the British genius who inspired the modern computer, protected Allied soldiers from Nazi attacks with his code-breaking prowess and was a closeted gay man — you’ve got yourself a film with Oscar buzz. (Casting Benedict Cumberbatch as the lead doesn’t hurt either.)
Overall, the movie works: It’s fun, it’s gripping and it features a brilliant performance from Cumberbatch. But like so many other Hollywood biopics, it takes some major artistic license — which is disappointing, because Turing’s actual story is so compelling.
The film mainly takes place during the early years of World War II, when the German war machine is overwhelming Britain. Frustratingly, the British can intercept German communications but can’t understand them. The Germans had encoded their communiqués on Enigma machines, encryption devices that could substitute letters in a message using any of about 150 quintillion possible settings. The filmmakers effectively portray a race against the clock as Turing struggles to perfect his crazy idea for a machine that could break the Enigma code.
In reality, Turing had already outlined the concept of a computing machine in a 1936 paper (SN: 6/30/12, p. 26) and had built a cipher machine while at Princeton in the late 1930s, says Turing biographer Andrew Hodges. By mid-1940, Hodges says, Turing and his team at Bletchley Park in Milton Keynes, England, were routinely decoding German Air Force messages with code-breaking machines, or bombes. Within another year the cryptanalysts, which included Joan Clarke (played in the movie by Keira Knightley), had deciphered the all-important naval messages that strategized U-boat attacks.
The biggest real-life drama is unmentioned in the film, Hodges says. In February 1942, the Germans adopted a more complex Enigma machine for naval communications, again putting the Allies in the dark. “It was a major crisis,” Hodges says. In desperation, Turing and American partners ran multiple bombes in parallel and used electronic components to speed up the code-breaking process. Finally, in early 1943, the Allies succeeded in cracking the code.
The consequences of the 1942 Enigma upgrade went far beyond the war. The introduction to electronics, Hodges says, offered Turing a practical means for incorporating his 1936 conceptual ideas into a revolutionary machine — the digital computer. “The scientific story is much bigger than just the Enigma problem,” Hodges says. “It was a great movement in which ideas and new technology came together.”
The Imitation Game ignores much of this history, and it also includes an egregious, historically inaccurate storyline in which Turing fails to report a Soviet spy to avoid being outed as gay.
Nonetheless, the acting, suspense and a surprising amount of humor make it a movie worth seeing. Just take some time after the movie to read up on Turing’s actual immense contributions to the war and modern computing.