Dreamers and Deceivers (26 page)

“Frank Birch doesn’t think I’m Don Quixote,” Alan shot back.

“Birch doesn’t understand your fancy math any better than I do!” Denniston retorted, his anger returning and his face becoming a deeper shade of red with every word. “That is to say, he doesn’t know an algorithm from an allergy. Birch is the head of the Naval Intelligence Section, and the only reason he believes the U-boat Enigma can be broken is because he thinks it
needs
to be broken!”

“Damn right it needs to be broken!” Alan could no longer contain his anger. “Listen, Alastair. The U-boat Enigma is the whole ball game. Cracking it is what mathematicians and logicians would call ‘necessary but insufficient’ to our survival. It’s ‘insufficient’ because Britain can still lose the war if it beats the U-Boat Enigma. Even if we manage to feed our people and arm our soldiers, we might still lose the war. But it’s ‘necessary’ because Britain cannot win the war
without
beating it. If we can’t feed our people or arm our soldiers, we absolutely
cannot
win the war.”

Alan felt like he was gaining some rhetorical momentum and he wasn’t about to stop. Denniston was in the military chain of command,
but Alan was still a civilian. He was free to speak his mind, which he’d never had much of a problem doing.

“In case you haven’t noticed,” Alan continued, “we live on an island. The food we eat, the raw materials that make our tanks and planes, it all comes from what we so magisterially refer to as the ‘Empire.’ That means cargo ships have to travel thousands of miles across U-boat-infested waters if we want to eat, put bullets in rifles, and pump gas into fighter planes. So long as we don’t know where those U-boats are, our ships can’t dodge them, and in that case, the demise of the United Kingdom is a question of when, not if.”

“Yes, yes, I know all this, but—”

“But nothing!” said Alan. “We lost two hundred thousand tons of cargo last month, and as the Germans build more U-boats—which they are doing as we speak—that tonnage of sunk cargo will double and triple and quadruple. If this continues we’ll never be able to amass the tanks, planes, and men to launch an invasion across the Channel to liberate France. Never mind that—we won’t even be able to feed ourselves! Is that what you want?”

“Well, no,” stammered Denniston, “but—”

“Then leave me alone,” said Alan. “I’ll work when I want, how I want, wearing whatever I want! And I’ll do what no one else on this island can do: I’ll break this infernal code.”

Alan stopped, tempted to leave it at that, but he couldn’t resist a grand finale. “Archimedes said, ‘Give me a lever long enough, and I’ll move the world.’ Well, if you’d just give me a little time and space, I’ll move Hitler’s armed forces right back to Germany, and then into history.”

Denniston decided to throw in the towel. There was no point in arguing with Alan Turing. He was too smart. And too stubborn. “You’re a messy, frustrating man, Turing,” Denniston said, turning to leave.

“Well, it’s a messy, frustrating world we live in, Alastair,” Alan replied, turning back to his notebook of diagrams and equations, and repeating, in a whisper, the couplet that he’d first heard at the Regent Street Picture House. For whatever reason, it always seemed to bring him a degree of comfort and serenity: “Dip the apple in the brew. Let the sleeping death seep through. . . .”

Bletchley Park

January 7, 1941

Alan Turing had invented a machine that contained dozens of smaller machines, each designed to replicate the work of a real Enigma. With dozens of replicated Enigmas, the machine made guessing mechanical, which allowed it to work at superhuman speeds.

But even that wasn’t nearly fast enough. Instead of taking trillions of years to decipher a U-boat Enigma code—as random guessing by hand would have done—Alan’s machine would take months, possibly even years. That was still way too long for the intelligence to have any value.

Alan hadn’t slept all night. Haggard and still wearing a wrinkled robe, he burst into Denniston’s office first thing in the morning. “The keys,” he exclaimed, “are the common words that the Germans use in many of their messages. Military ranks. Weather forecasts. ‘Heil Hitler!’ We can look for these words by looking for clumps of letters that resemble them.”

“But how can any clump of encoded letters resemble a word?” asked Denniston. “Isn’t every encoded letter randomly generated by the Enigma?”

“Not quite!” Alan said excitedly. “There’s one thing about every letter that isn’t random. Because of the Enigma’s reflector, no letter is ever encoded as itself. Sure, a letter might remain the same after first entering and exiting the plug board, but once it has gone through the rotors, no letter is ever encoded as itself. The real letter ‘c’ is never encoded by the Enigma as ‘c.’ The real letter ‘d’ is never encoded as the real letter ‘d.’

“All you have to do is find a commonly used word, like ‘Admiral,’ ” Alan explained. “Write it out. Now slide it along the encoded text. We’re looking for a seven-letter combination in the encoded message that does
not
have ‘a’ for the first letter, or ‘d’ for the second letter, or ‘m’ for the third letter, et cetera—all the way through the seventh letter.

“If you find a seven-letter combination without those letters in those places, then there’s a good chance that those letters are the encoded word for ‘admiral.’ The longer the word—let’s call it our crib—the
longer the crib, the more likely that this process will work. For example, the phrase ‘continuation of previous message,’ which the Germans use hundreds of times a day, would be a perfect crib.”

“Okay,” said Denniston, “but how does that help you decipher the rest of the message?”

“That’s where a machine comes in, Alastair. We just have to reprogram the electronic brain we’ve already built.” Alan was smiling at the thought of it. In 1935, he’d first dreamed of what the math world was currently calling “Turing machines.” Although the device he now imagined was far less universal in its capabilities than a “Turing machine,” the principle of using a machine to imitate the mind of a man was the same.

“I’m not sure I follow,” said Denniston.

“You don’t have to,” Alan replied. “Just tell the big man on Downing Street that I know how to build a machine that will break the U-Boat Enigma. Once it’s built, we’ll be deciphering thousands of messages every day, not after weeks and months of analysis of a single message, but after a few hours. By this time next year, convoys will know where every U-boat is and how to dodge them from New York to Southampton. We’ll go weeks without so much as a single successful U-boat attack!”

Of course, the machine would always be a work in progress, as code-breakers discovered more and more cribs, and as Bletchley adapted the machine to changes in the Nazi code-making schemes. Some weeks and months would be much better than others. But the ever-evolving machine soon proved far faster than anything else at breaking codes, and time, as Alan knew, was of the essence.

And not just in the waters surrounding the United Kingdom.

New York City

November 13, 1942–March 23, 1943

As Alan’s ship sailed into New York Harbor, he thought about the Anglo-American alliance. For the first two years of the war, the British had fought without their American cousins. Against all odds, they had
survived. Then, after the Japanese forced the United States into the war by bombing Pearl Harbor in December 1941, the alliance that would eventually win the war was born. It was at that “very moment,” according to Winston Churchill’s later reminiscences, that he “knew that the United States was in the war, up to the neck and in to the death” and that, as a result, “Hitler’s fate was sealed.”

Since then, the British had grown accustomed to the new reality that Americans were assuming greater influence and power, but that didn’t mean the British had nothing to teach their American allies—especially when it came to battling the Nazi U-boats that were sinking American ships. Hundreds of those ships littered the depths of the Atlantic along America’s eastern shore. Now, more than a year into the Atlantic Alliance, both sides were undertaking an unprecedented sharing of intelligence based on their common enemy.

That collaboration of intelligence had taken Alan from his embarkation in New York City to meetings in Washington, D.C. There he shared his code-breaking insights with American cryptanalysts at “Communications Supplementary Activities,” the U.S. Navy’s code-making and code-breaking service.

About two months later, Alan returned to New York, where he spent most of the next two months in a large building at 463 West Street, near the city’s piers, and under whose roof some of the best scientists on the continent were working twelve-hour days to design the devices the Allies needed to win the war. It was called Bell Laboratories.

On his first day at Bell Labs, Alan was shown a huge, climate-controlled room with thirty different machine components—mounting bays—each one seven feet long. “This machine,” said Frank Cohen, the scientist giving Alan his orientation tour, “is what will soon make it possible for my president to speak to your prime minister without the German Führer knowing what they say.”

Alan inspected the thirty large, rectangular mounting bays. “Secret speech?” he asked. “You mean it will scramble a transatlantic phone call like we scramble transatlantic telegrams?”

“Exactly,” said Cohen. “We installed an experimental model in
November, and now we’re building an operational one. You’re the first Englishman to set eyes on it.”

As if on cue, Alan’s bright blue eyes glowed with excitement. Men had been encoding the written word for millennia, but a machine that could easily and reliably encode the spoken word would be revolutionary.

“Of course,” continued Cohen, “there are dozens of kinks in the system that we’re still trying to solve. To be perfectly candid, some of us are feeling a bit stumped. We were hoping you could lend us a hand.”

Alan stared in wonder at the machine and nodded in assent. It was clunky, fragile, and not even operational, but, to Alan Turing, it was beautiful—another testament to what the creative mind of man could build.

“Well, when can you start?” asked Cohen.

Alan smiled, still staring at the machine.

“I already have.”

Normandy, France

D-Day: June 6, 1944

Fifteen months after Alan returned to Britain from the United States—where he had helped make the secret-speech machine operational, contributed to a host of other projects at Bell Labs, and taught his American counterparts in Naval Intelligence what he knew about the Enigma and code-breaking—the Allies launched the largest amphibious invasion in the history of warfare.

“You are about to embark upon a great crusade,” General Dwight D. Eisenhower had told the men of his mighty armada. “The hopes and prayers of liberty-loving people everywhere march with you.”

With them were tanks, artillery, planes, and an arsenal that matched the German Reich’s mighty war machine gun for gun and shell for shell.

Almost every element of the arsenal, including one hundred thousand American and Canadian soldiers, sailors, and airmen, had crossed
a once-perilous ocean—an ocean that Alan Turing, more than any other man, had made safe from Adolf Hitler’s Nazi U-boats. He had cracked the Enigma machine, which not even the genius code-breakers at Bletchley Park had thought was solvable. Alan Turing had not only been important in bringing about Germany’s defeat, but absolutely essential.

For his indispensable efforts, His Majesty’s Government awarded him the Order of the British Empire.

Eight Years Later

Manchester, England

February 7, 1952

“But how do you know the name of the man who robbed your house?” asked the incredulous policeman standing in the messy living room of Manchester University’s most distinguished computer scientist. The police officer had never met a computer scientist, let alone seen a computer, and after arriving at Alan’s house for the first time yesterday, he hadn’t particularly warmed to this one.

“I just know, okay,” replied Alan. He was already exhausted by the stress of his home being burglarized a week earlier and the news he had received three days earlier that a former fling was in cahoots with the robber. Yesterday he had made a halfhearted attempt to report the crime without revealing that the burglar’s accomplice was an acquaintance of his.

“Well, that’s not what you told us yesterday,” said the gruff, overweight bobby. “We checked out the story you gave us yesterday and it was full of holes. How do you actually know the name of your burglar?”

“Fine,” said Alan, “I’ll tell you truth.”

He hated lying. He had no talent for it. It was out of character for him to be anything less than brutally honest, and he felt relieved by his instantaneous decision to come clean about the false story he had concocted yesterday.

“I was at a bar,” Alan began. “And a man sat down next to me. He wasn’t a particularly bright man, or even an especially good man. He’d been in and out of jail for some petty larcenies. Against my better judgment, we became friends. And that friend later met another man in another bar. And that other man was the one who robbed me.”

“That makes no sense at all,” the policeman said, confused. “How do you know the man your friend met is the man who robbed you?”

“A couple of days after the burglary,” explained Alan, “I met my friend again, the one from the bar, and he told me the name of the burglar, who apparently assumed that even if I knew his name, I’d never report him to the police.”

“And why on earth would he assume that?”

“Because, if you must know, my friend was more than a friend,” said Alan. “We were romantic friends.” And then, just to make sure the slow-witted officer knew what he meant, Alan added, “It was an affair. This man and me, we had a brief . . . regrettable . . . affair.”

Alan thought it felt good to get that off his chest. His life’s work had been a series of searches for the truth, and it had gone against every bone in his body to hide the truth when telling the police how he came to know the name of the man who’d robbed his house. Honesty had always been, if not convenient, at least instinctual for him. In Germany, he hadn’t pretended to admire the Führer. At Bletchley Park, he hadn’t pretended to respect Denniston. And now, today, in his own living room, he wasn’t about to pretend anything. The representatives of His Majesty’s Government at Bletchley had almost certainly known he was gay when he was breaking the Enigma code, and he saw no reason why the representative of the government who was investigating the burglary of his home shouldn’t know it as well.