Unbreakable--The Spies Who Cracked the Nazis' Secret Code Page 2

  At the palace, grand arches and columns framed a courtyard around the Tomb of the Unknown Soldier. Lawns and hedges sprawled beyond the colonnade, joining the two buildings of the Polish General Staff, the highest offices of the Polish armed forces. Inside, Major Gwido Langer was waiting.

  Bertrand wore the small half smile of a man prone to keeping secrets; Langer carried himself with the intense, confident posture of a man used to exploiting any weakness.

  Twice, while a soldier during the First World War and in the skirmishes that followed, Langer had become a prisoner of war. He had escaped, too, and had trekked hundreds of miles through Siberia to rejoin his army. Langer’s bravery had become apparent during these wars, but so, too, had his grasp of military strategy; he witnessed and understood how decrypting intelligence had changed defeat to victory in key battles. It made such an impression that Langer devoted the rest of his life to ensuring that Poland could break other countries’ codes and access their information. By 1929, Langer had become the head of the Polish cipher office—all of Polish counterintelligence that touched codebreaking was under his command.

  And now Bertrand said he had something new.

  Inside the Saxon Palace, Bertrand pulled out the photographs. He laid Enigma manuals and instructions in front of Langer. Were they really as worthless as the French and British had said?

  Langer took one look, and immediately there was “an explosion of amazement and joy,” Bertrand remembered. As soon as he collected himself, Langer rushed out of the room and returned with two colleagues.

  “This is extraordinary and unexpected!” one of the Polish codebreakers cried.

  Bertrand let them have forty-eight hours to examine the documents. Two days later, when the Frenchman returned to the Saxon Palace, Langer and his colleagues were waiting. “They were radiant,” remembered Bertrand. “The Schmidt documents were welcomed like manna in the desert.”

  “Vous avez fait donner l’artillerie lourde!” [“You brought out the big guns!”] Langer said, not mincing words. “This is crucial for the future of our research. We cannot express enough our gratitude.”

  For his part, though, Bertrand couldn’t help but cringe. After all, his own country’s supposedly sophisticated, advanced, scientific Deuxième Bureau had failed to see any advantage to Schmidt’s materials.

  Langer noticed. “You do not have the same motivations we do,” he said graciously. Poland, not France, was Germany’s immediate military objective.

  As they parted, Langer couldn’t help asking for just a bit more.

  “If we had access to one or more of the monthly tables reporting the daily modification—even if they were obsolete—we would progress much further and save years of work,” he said.

  Inwardly, Bertrand blanched. Asché risked enough as it was; to ask him to bring the most sensitive material would put him in even more danger. But Bertrand promised to relay Langer’s request to their spy.

  As they parted, they agreed to keep talking. Bertrand offered to share any additional information that their spy might provide, and he would inquire specifically about obtaining the manuals and keys Langer requested. In return, Bertrand suggested that any information or breaks in Enigma discovered by the Polish codebreakers would then be shared with France.

  It was a promise, Bertrand thought.

  It was a proposal, Langer decided.

  THREE

  THE MACHINE AND THE METHOD

  THE ENIGMA MACHINE was immensely complicated. Though it was the size and shape of an ordinary typewriter, it was actually an instrument designed to maul coherent messages into incomprehensible clumps of letters.

  Enigma with machine lid open.

  [National Museum of the US Air Force]

  It all began when an Enigma operator pressed a key on the keyboard.

  First, the electrical signal ran from the keyboard through the plugboard (wires on the front of the machine that connected pairs of letters). Then the signal was routed through three rotors and a reflecting drum. The reflecting drum reversed the direction of the electrical signal and sent it back through each of the three rotors, the plugboard, and finally up to the windows at the top of the machine, where it caused a single letter to glow. The original letter typed on the keyboard was now encrypted into a different letter.

  What happened next changed everything.

  Once the operator released the key he had been pressing, the machine began to transform. Inside, the rotors started to spin. Sometimes only one rotor turned. Sometimes two or all three rotors turned. With every movement, a brand-new electrical path was created.

  Letter by letter, an Enigma operator typed in his original message. Letter by letter, the machine twisted and spun to light up encrypted characters, letters that formed words, which were gibberish and meaningless to anyone looking at the new message.

  Once the entire message had passed through the machine, the operator sent the encrypted letters over the radio. Far away, a receiving operator tuned his own radio to a certain frequency and listened in.

  Now came the problem of decrypting—taking the encoded message and turning it back into readable German. The only way for the receiving operator to do so was to match his own Enigma machine to the sending machine. The rotors, which could be rearranged, had to be in the same order. The inner core and outer shell of each rotor could twist against each other, and these inner and outer parts had to be matched correctly (called the ring setting). Likewise, the starting angle of each whole rotor (inner and outer pieces together), which could be rotated to a different initial position, needed to be the same. The plugboard, too, had to be connected using the same pairs of letters.

  Close-up of the three Enigma rotors. The letters around the outside can rotate with respect to the inner wiring of each rotor.

  [TedColes via Wikimedia Commons]

  Enigma plugboard with several pairs of letters connected.

  [Bob Lord via Wikimedia Commons]

  Once all this setup was complete, the receiving operator could begin typing in the encrypted message. As he did so, letter by letter, the original message was illuminated in the windows.

  But if even one setting was off, if there was even one difference between the two Enigma machines, the message could not be deciphered. Instead of German words, the illuminated letters would continue to form words that were utterly meaningless.

  Some settings—like the rotor order, the plugboard connections, and the ring setting—were written in daily codebooks provided to each Enigma operator. Other settings, though, like the initial position of each rotor, changed with every message.

  The sending operator had to have a way of telling the receiving operator how to set up his machine.

  So, before every Enigma transmission, the sending operator would also include an unencrypted preamble to his message. This beginning section included three letters, one for each rotor. These letters explained the starting angle for each rotor. They were called the indicator settings.

  The indicator settings were so important that the Enigma operator repeated them in his preamble.

  The Germans knew the Enigma messages couldn’t be read unless the machines matched perfectly. They didn’t want to take the chance that the indicator settings might be lost to static or a miscommunication. So they repeated the settings. But, in doing so, they overlooked a fundamental truth:

  Never repeat something that you want kept secret.

  * * *

  The numbers were astronomical.

  There were 403,291,461,126,605,635,584,000,000 ways of creating the wiring within the rotors and 7,905,853,580,025 possible connections within the reversing drum alone. As if that wasn’t enough, a plugboard with six pairs of connected letters created another 100,391,791,500 possible settings.

  An Enigma codebreaker later wrote that “the Germans reasoned, even if the opponent got his hands on one of the military machines, for example, as a result of military action, not knowing the key [daily settings], he still would be
unable to read any message.”

  It certainly seemed like the Germans were right.

  FOUR

  RECKLESSNESS

  1932—the German-Belgian border

  BERTRAND HAD HEARD the plea in Langer’s voice. The Polish codebreakers needed more information.

  But so did everyone else.

  Schmidt had quickly become the most valuable spy among all of France’s assets. Along with cipher manuals and instructions, he provided a stream of information on German armament (military weapons), troop movements, war games (drills and strategy for coming battles), and military goals.

  At one meeting between Schmidt and agents of the Deuxième Bureau in the fall of 1932, Bertrand’s supervisor, André Perruche, pulled Schmidt aside. It had taken Perruche all night to photograph the latest stack of documents Schmidt brought, and the information had made the intelligence officer nervous.

  “In the long report that you brought, I noticed some information that could only come from a high level of command,” said Perruche. “Can you give me the source?”

  Schmidt smiled. “It’s my brother. Since July 1, he has been the director of the Kriegsakademie [War Academy].… He has learned things that would truly shock you.”

  Schmidt regularly “borrowed” documents from his brother. In page after page, each report from the military academy told the same story: the Germans were preparing for war.

  The information Schmidt brought was so important that Bertrand and Lemoine paid, happily, whenever he requested a rendezvous. But Schmidt put himself at risk every time he brought them secrets.

  By the fall of 1932, one year after they had first started meeting, Bertrand and Lemoine had perfected their system for keeping Schmidt safe. Schmidt had shown Lemoine a method of reading invisible ink.

  “It is simple and relatively reliable,” Lemoine explained. “He has a good background as a chemist. He writes to us between the lines [of a regular letter] with a simple solution of sodium chloride, holding the letter over steam for about 30 seconds and then covering the contents with a starch solution.”

  Upon receiving a letter from Schmidt, Lemoine would carefully wipe it with a cotton cloth soaked in silver nitrate. He’d press a hot iron against the wet paper, and Schmidt’s invisible message requesting the next meeting would suddenly appear.

  Then the traveling began. Along the Belgian-German border, Schmidt snaked his way through “an incredible tangle of fields, gardens, and houses,” remembered one agent. “Some buildings had their entries in one country and one or more exits in another.” From the train station where Schmidt ended his rail journey from Berlin, he then traveled another six miles by tram and foot through four different towns.

  “Your route is impeccable, but it’s so long,” Schmidt once complained to Lemoine.

  The distance was both curse and protection. In the event that Schmidt was followed by suspicious German agents, the route would help throw off any potential tails. But the longer Schmidt traveled, the riskier the journey became. He had no access to diplomatic bags (labeled containers that were illegal for a foreign government to search or seize) like Bertrand used at the Saxon Palace in Warsaw. Schmidt carried whatever information he brought.

  He always brought information. And Lemoine always paid.

  Tens of thousands of marks—the equivalent of hundreds of thousands of dollars in 2022—changed hands. “At this rate,” the head of the Deuxième Bureau observed, “[Schmidt] will cost us as much as all of our other informants put together!”

  He was worth every penny.

  After the first few meetings, though, everyone realized it would not do to have so much cash on hand, and they came up with a better system to pay Schmidt. Schmidt waited at home in Berlin for a postcard, written with a dull message about something trivial, sent through the regular mail. That was his cue. He then went to the post office, showed his ID, and received an envelope waiting there for him. The envelope contained a luggage ticket. At the train station, Schmidt retrieved the bag associated with the ticket. His payment was stuffed inside.

  Bertrand and Lemoine did all they could to protect Schmidt where the Deuxième Bureau was involved. But they couldn’t protect him from himself.

  Schmidt’s shabby clothes had vanished, replaced by expensive suits. He took his wife on a six-week vacation to luxury resorts around the Continent. At home, he added rooms to his house, drank expensive wine, and showered his mistresses and girlfriends (there were many) with presents.

  Still, even as Schmidt-code-named-Asché began flaunting his newfound wealth and Bertrand and Lemoine worried over his safety, they couldn’t deny him more money. He was far too valuable an asset to drop. The Deuxième Bureau would keep on paying him for as long as he brought them information, and they would hide both him and the money as best they could.

  But not even Lemoine could keep an eye on Schmidt all the time.

  FIVE

  THE VIOLENCE OF WORDS

  November 8, 1923 to 1932—Munich, Germany

  THOUSANDS OF PEOPLE cowered inside the Bürgerbräukeller beer hall when thirty-four-year-old Adolf Hitler raised his gun, fired a single shot into the ceiling, and announced that the hall was surrounded by his followers. The beer hall, a common place in Germany to hear political speeches, was packed that night, full of people waiting to hear from a trio of police, military, and civil service leaders. Suddenly, everyone was focused on Hitler instead.

  He took the German leaders to a back room. Together with a famous general from World War I, Hitler convinced the three to turn over leadership of the local government to the National Socialists German Workers’ Party, or Nazis. Triumphantly, Hitler reappeared in the still-crowded beer hall and made a speech extolling Nazi ideals. More than two thousand men, most of whom hadn’t supported Hitler before the night began, marched out of the beer hall together, intent on overthrowing the rest of the government.

  But by the next day, the putsch, or coup, had failed. Instead of seizing power, Hitler was arrested for the crime of high treason.

  Yet Hitler’s ideas had already spread, and people rallied around him. He was quickly turning into a celebrity, and his trial became a spectacle, serving as a platform for his views. Hitler’s speeches in his own defense were reprinted in newspapers around the country, and rather than exposing him as an insurgent and instigator, the trial became a means of gathering more people to his cause. In the end, he was given an incredibly lenient sentence: five years in the modest Landsberg Prison.

  Hitler’s spacious, comfortably furnished room could hardly be called a jail cell. Visitors came and went at their leisure, often spending time with Hitler unsupervised. On his birthday, Hitler hosted forty people at a party to celebrate. In the end, he only served nine months of his sentence before being released.

  But Hitler had done more than just socialize while in prison. For nine months, he wrote.

  Across page after page, in his book Mein Kampf [My Struggle], Hitler spelled out the problems facing the German people, as he saw them. They were suffering from poverty and unemployment. They lived in a country that was reduced from the empire it had once been. Ordinary citizens were bowed down, made to bear the brunt of shame from the German loss in World War I.

  It wasn’t their fault, Hitler wrote. The German race was a class of people far superior to the rest of the world, he told them. They needed to blame everyone else.

  Jews and communists topped his list, but a wide range of races, identities, and ideologies fell under his condemnation.

  “All who are not of a good race”—that is, blond-haired and blue-eyed Germans—“are chaff,” wrote Hitler. Anyone not of this “pure” race, he claimed, should be eliminated. He made no attempt to hide the horrific measures he was willing to take to ensure this happened: it “must necessarily be a bloody process.”

  As the German people grew more dissatisfied, Hitler fed them his ideas and gave them races and religions to hate. Slowly, Hitler and the Nazis began to gain seats in the
Reichstag, the lower house of the German legislature. By July 1932, the Nazis held more than a third of the seats.

  All the while, as he and his followers gathered support, Hitler was brazen about his goals. In one speech, he proclaimed, “Either the enemy walks over our dead bodies or we over theirs!”

  From his failed Beer Hall Putsch, Hitler knew that he could not overthrow the government by force. Speeches, not riots, and the votes that pollical rallies brought would steadily help Hitler to find power.

  The violence, he promised, would follow.

  SIX

  A FOUR-CHARACTER ANSWER TO A SIX-WORD QUESTION

  1929 to 1932—Poznań to Warsaw, Poland

  LANGER NEEDED HELP.

  The violent rhetoric rising from Hitler in Germany, directed not only at Jews but at the Polish people just to the east, made it imperative that Poland understand and anticipate what was coming.

  But the new, mechanical German cipher—Enigma—would not yield.

  With all of the best men at the cipher office trying and failing to break Enigma, Langer went for a different tack. Most codebreakers were linguists, experts who used known traits and characteristics of language to translate intercepted messages. To crack Enigma, Langer knew he would need to bring in people adept with a new set of tools.

  Antoni Palluth was a good place to start. Palluth was an expert at miniature electronics and spyware—radios that could fit into the palm of your hand, easily some of the smallest equipment of their day. Palluth had invented them, and he was the one who had to fix them when they broke. Polish spies working behind foreign borders could hardly be expected to take equipment to a local store to be repaired. Instead, Antoni would go. His wife, Jadwiga, would silently grimace as Antoni removed his pistol from the kitchen cabinet and packed it along with his clothes.