Alan Mathison Turing. In the worst of times extraordinary minds achieve the impossible. Photo Credit: Fellowship of the Royal Society.

By Catherine Revland

This is the third article in a series, You Must Remember This, about World War II and its relevance to our times.

“To POTUS: The scene has darkened swiftly…The weight may be more than we can bear” (intercepted cable from Churchill to FDR, read by the German High Command, 1941).

“The Fuhrer is not just a lunatic. He is an evil genius. The weapons in his armory are like nothing in history. The most sophisticated apparatus for conveying top-secret orders through the ether guides the Nazi war machine…If we decipher their codes, our political leaders might understand the depth of Nazi wickedness” (Sir William Stephenson—“Intrepid”—to FDR, 1942).

“Every time I hear a creak in the house, or a step on the street outside, I’m sure they’re coming for us” (Diary of Anne Frank, 1943).

In 1942, the darkest year of history’s most destructive war, during a fireside chat on George Washington’s birthday to a nation still reeling from the shock of Pearl Harbor, FDR talked about another moment in history when Americans faced seemingly insurmountable odds: “Washington’s conduct in those hard times has provided the model since then, a model of moral stamina. In a sense, every winter was a Valley Forge.” What the president didn’t tell the country was that the Germans had deciphered the British naval code. Allied ships were being torpedoed faster than they could be replaced, a ten-fold increase in a single month. Of the seven million newly drafted Americans being sent to the battlefront, how many would die in transport across the Atlantic?

That February William Stephenson paid a visit to Prime Minister Churchill, whom he found in deep despair. “It’s most galling that the enemy should know just where our ships are,” said Churchill. Stephenson then reported what he had learned on his latest trip to Germany: that the enemy had produced an even more powerful version of their Enigma machine. Breaking the German naval code, the most impenetrable version of their enciphering system, was now the only way to defeat them. Pondering this latest piece of bad news, Churchill said, “The sinews of war have become whispers in the ether.” Then, taking Stephenson by the arm, he told him, “If you recover the whispers, I’ll find the interpreters of what they say.” Would that interpreting those recovered whispers had been as simple as a pat on the arm.

But it was not Churchill who needed to be convinced of his country’s desperate need for intelligence. It was his countrymen. Many of them called intelligence by another name—spying—a most ungentlemanly act, like reading someone else’s mail. Nevertheless, Churchill loved his codebreakers at Bletchley Park, calling them “my geese who lay golden eggs and never cackle,” and he had nothing but praise for the brilliant young mathematics professor he had recruited from Cambridge to be in charge of Hut 8, whose work entailed breaking the crucial Enigma naval code. His name was Alan Mathison Turing. Historically speaking, he could not have been sent to a better place.

The “Prof”

In laypersons’ terms, the Enigma was a system of electrical wires attached to a number of rotors that randomly substituted one letter for another, over and over. Its code key (like a password) changed each day. The Bletchley approach was to go through all the possible positions—a painstaking, mind-numbing guessing game—but it was much too slow to be useful. Something had to change, and quickly. One day, delving deep into the heart of things in the way he knew best, through mathematical theory, Turing had an epiphany. Language was full of redundancies (unnecessary letters familiar to anyone who thumbs a text) which, if eliminated, would speed up the deciphering process enormously. It wasn’t necessary to go through all those positions! The theory he developed was put into practice and the result was the Turing machine, electric, colossal in size, and so complex that only he knew how it functioned.

For a while Turing’s machine was a great success that saved many lives; but in February of 1942, when the Germans came up with a new Enigma that doubled the number of rotors, Turing knew an electric machine would never be fast enough. The only option was an electronic version, which presented yet another problem—the British were far behind in the electronic relay race, and there was no time to waste. However, Turing and his colleagues had heard about rooms that were full of high-speed electronic equipment at Bell Labs in the U.S., equipment that worked. It was one of history’s do-or-die moments, and it had to be Alan Turing to make the voyage to America, on the Queen Elizabeth (speedier than any U-Boat), because the beloved “Prof” was the only one who knew everything.

The story continues in the next article, “Alan Turing Comes to Bell Labs.”

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