X, Y & Z

by Dermot Turing

  • • •

  In one of the most significant undercover operations of World War Two, a small group of men converged secretly on a long-disused building next to the railway station serving a crummy, red-brick town. They were dressed in plain clothes and had been informed of the password in case of challenge. They had also been told that the official address of their destination was ‘Room 47, Foreign Office’, which was likely to deceive no one, at least not for long, for the actual place was a long way from Whitehall. It was a Victorian concoction, a fantasy building created from dozens of architectural styles through the ages and served up like canapés, all the different pieces presented alongside each other on the façade. Perhaps the most remarkable thing was a stockbroker Tudor gable poking out of an immense bronze dome. The hideous building was a ‘maudlin and monstrous pile’ and its name was Bletchley Park.

  The secret operation was the mobilisation by Alastair Denniston of the ‘men of the professor type’. Upon the declaration of war, the professors were called in, most arriving during the first week of September 1939. They included Dilly Knox and Alan Turing, who were immediately assigned to the cottages around the stable yard behind the main house. It would not do to have the administrative staff treading on the toes of the code-breakers, or maybe the thinking was that the administrative staff wished to preserve their sanity from excessive exposure to the idiosyncratic code-breakers.

  Although the fighting war in Europe was soon over, it was clear that the war against Enigma had barely begun. The priceless intelligence gleaned at the Pyry meeting in July had furnished the British not just with knowledge about the structure of the Wehrmacht machine but also with ideas on how to find the daily settings. By their own admission, the Poles had not been making much headway in finding the settings during 1939. The extra rotors introduced in December 1938 were part of the problem; the switchover to a fresh ground setting for each message was another; and to cap it off, in January 1939 the Germans had added three extra cross-plugging wires to each Enigma machine, vastly increasing the number of possible cross-pluggings. All these factors contributed to the conclusion that the successful pre-war Polish methods were becoming outdated.

  The Polish bombas, and another method of finding settings invented by Henryk Zygalski using perforated cardboard sheets, relied on the occurrence of ‘females’, repeated letters showing up in the indicator which the Germans transmitted at the start of a message. But females were an endangered species. If the Germans changed their procedures again and stopped the insecure double encipherment of the indicator, all techniques based on searching for females would become redundant at once. The British knew that they not only needed to improve on the Polish techniques, they needed to create new ones which did not depend on finding females.

  Alan Turing, aged 27 in September 1939, brought to Bletchley a grounding in mathematical theory coupled with a very practical approach to machines. He visualised mathematical problems and their proofs in machinery. Turing’s most famous paper, published in 1936, was called On Computable Numbers, with an Application to the Entscheidungsproblem. It postulated a mechanical device into which instructions could be fed. This proved, in due time, to be the theoretical blueprint for a programmable computer. Since 1936, Alan Turing had not just been theorising, he had also been building various machines, such as a mechanical multiplier and a cog-wheel machine to find answers to a problem of the uneven spacing between prime numbers. His new task at Bletchley Park was to invent a machine to find the settings used by the Wehrmacht on their Enigma messages, one that did not depend on double encipherment of indicators and the existence of females.

  On the upper floor of one of the cottages, Alan Turing set to work. As all code-breakers know, the process of code-breaking is immeasurably easier if you know – or can guess accurately – some of the content of the message. The Scarlet Pimpernels included materials discussing a technique called the mot probable, used by both Knox and Henri Braquenié to attack the commercial model of the Enigma machine.3 The British called the probable word a ‘crib’, following Hugh Foss’s choice of the schoolboy word for using the answer in the back of the book. Alan Turing’s machine to attack the Wehrmacht Enigma was going to be based on cribs.

  The basic idea was similar to that of the Polish bomba. Turing’s machine would go through all 17,576 possible rotor configurations and look for a possible start position which could have caused all the letters in the crib to become enciphered as the gobbledegook which had been intercepted. All the letters in the crib could be electrically tested at the same time. This was essentially what the bomba did with the six-letter indicator, but Turing’s machine could test a crib of any length. Better still, the new, powerful machine would help with the problem of the plugboard. Whereas the Poles had found it necessary to use trial-and-error to work out the cross-pluggings, Turing’s machine would offer up one potential cross-plugging as part of the solution it proposed. That one cross-plugging would prise open the remaining settings for the day, would unravel the rest of the Enigma set-up. The design was completed in the first few weeks of the war and the engineers were called in. Without the priceless gift of the theory of the bomba, it is hard to imagine that Alan Turing’s crib-checking machine would have been conceived so fast, if at all. In a small acknowledgment of its intellectual provenance, the machine designed by Turing was going to be called the ‘Bombe’.

  • • •

  Major Maksymilian Ciężki had received special orders on Tuesday, 5 September 1939.4 The constant raids on Warsaw meant that the secret outstation of the Biuro Szyfrów at Pyry was at risk. The equipment still on site was to be destroyed and explosive charges were set to blow up the radio tower at the appropriate time. Henryk Zygalski spent the day burning papers. Suddenly, it dawned on Ciężki that the orders for destruction and evacuation did not cover the AVA factory, where there were Enigma rotors and machines and documents that would compromise the Enigma secret if they fell into the hands of the German forces. Despite the bombs and chaos across Warsaw, Antoni Palluth and a team from AVA got there in time. The assets were whisked off to be hidden in the eastern suburbs. Now the time had come for the code-breakers to leave.

  When, eventually, the code-breakers did get going, the train journey was even more of a nightmare than Barbara Różycka’s account reveals. After a day of constant air raids, their train collided with another in the middle of the night. Some of the party – but none of the code-breakers – were hurt. Zygalski and his colleagues had to get the crushed wagons off the line. The focus of the bombing had shifted to Siedlce, the next town on their route, which was now ablaze. They had been going two and a half days and had managed a whole 80km. Even if they got as far as Brześć – and they were not even halfway there yet – the Romanian border, where they were to join the regrouping army, was still 400km further on.5

  On 17 September 1939, the Soviet Union invaded Poland from the east.

  On the same day, the French began a withdrawal from the Saarland, which they had occupied for just over a week.

  The Russians moved up to a pre-agreed line, closely modelled on a historical one drawn by a Polish expert in London in 1919. With some local deviations it was the Curzon Line. The British approved then and they were hardly in a position to complain now. For Russians, it was nothing other than recapture of what they had lost in 1920. For Germany, the logic was similar. West of the line, reinvigorated German culture would bring to Poland the benefits of concentration camps, anti-semitism and hunger. To the East, the USSR would offer the Gulag, political re-education and hunger.

  The Battle of Poland was over, and with it, the war. For the fourth time in its history, Poland had been partitioned. As with the country, so with the families. Barbara Różycka and little Maliznota would have to stay behind. Gwido Langer, Maksymilian Ciężki, Marian Rejewski and Antoni Palluth were all exiled, cut off from their families. Poland, and its people, had ceased to exist.

  • • •

  When, on 27 Septem
ber 1939, Warsaw finally surrendered to the Germans, life for those left behind became no easier. The Poles were not going to give in, whatever their leadership might be doing. The Palluth household at Marshałkowska 19 became a focal point for the underground. Despite the Luftwaffe’s best efforts, the AVA factory had not received a direct hit and valuable equipment was stocked there which could help the nascent underground resistance movement. The Gestapo reacted to the potential for an insurgency with a decree that all wireless equipment must be surrendered by a certain date, failing which any Pole found in possession would be subject to the extreme ultimate penalty. The materials had to be sneaked out of AVA. Hiding places around the city were few, overlooked, and dangerous. The aristocratic Mrs Palluth was not going to allow fear of reprisals to get in the way of her responsibility as the factory owner’s wife. The apartment at Marshałkowska 19 had a long, wide hallway, wide enough for her young son to have learned to ride his bike there. The hallway would do just fine to store the dozens of boxes of radio equipment spirited out of the factory.

  The way out. Gwido Langer’s sketch map of his escape route from Poland in September 1939. (The Józef Piłsudski Institute, 238–246 King Street, London)

  The goings and comings into the apartment building in Marshałkowska did not go unnoticed by the Gestapo. One day the doorbell rang. Jadwiga Palluth told her son Jerzy what was going to happen. Most mothers would tell their 8-year-old to hide. Not her. ‘You will watch and listen. It is your duty, to bear witness.’ She opened the door for the scene to begin.

  In perfect German, immaculately dressed and with respectful etiquette, Mrs Palluth greeted the officers from the Reich’s Secret State Police. ‘In this country, we have the custom that officers remove their hats and side-arms on entering a private house.’ It was clear who was in charge.

  ‘Jawohl, gnädige Frau.’ The weapons and hats were deposited on the side table. Next to the rows of stacked boxes, all containing the incriminating material. ‘Was ist das?’ It was inevitable that they would ask.

  Mrs Palluth, ever in control, did not blink. ‘Since you ask, it is in fact radio equipment.’

  ‘What? Did you not know about the decree which required you to surrender all wireless and radio equipment? We could arrest you and you can be shot!’

  Mrs Palluth looked the senior officer straight in the eye. ‘Oh yes. Of course. There is just one problem. Perhaps you would care to lift one of these boxes?’ It was far beneath the dignity of a Gestapo officer to do such a thing, but the point was made. ‘Each of them must weigh about a hundred kilos. How am I supposed to take them anywhere? I’m so glad you called, you can take them with you.’

  The Gestapo men looked at each other. ‘Jawohl, gnädige Frau. We’ll send a van round.’

  Mrs Palluth was winning, but the Gestapo were not finished yet. ‘We need to know where your husband is.’

  ‘You had better come in and sit down. Would you care for some tea? Unfortunately, in view of the situation, I can only offer you herbal tea.’

  The Gestapo knew she was stalling; they stayed put. ‘We need to know: where is your husband?’

  ‘I can only tell you what I know. I last saw him in September. I have had no contact. I assume he must have perished in the war.’

  It was true, but it was not an answer they could accept. ‘At least you must have some of his belongings.’

  ‘Of course. Give me one moment.’ Young Jerzy sat, watching the Gestapo men, while his mother went into the room where Antoni Palluth kept his books. ‘Here.’ She handed the officer a leather-bound volume. It was a school prize book, extolling the glories of Kaiser Wilhelm’s High Seas Fleet, which had so nearly smashed the British at Jutland. The book pre-dated that battle; it pre-dated Polish independence. Inside, in the Kaiser’s own handwriting, a conventional statement of congratulation and encouragement to Antoni Palluth on coming top of his class. ‘It is one of his most treasured possessions.’6

  Like Jutland, the encounter might have been a tactical draw, but it was a strategic victory. Jadwiga Palluth was not beaten yet.

  • • •

  While the BTM company in Letchworth were trying to convert Alan Turing’s Bombe design into engineering reality, on 18 October 1939, Alastair Denniston received some truly shocking news. Playing the stage magician as always, Gustave Bertrand had produced a rabbit from his képi. To be precise, a whole family of them: the Polish code-breakers had magically appeared from nowhere and they were working in his unit in Paris.

  Like all good magicians, Bertrand had been unwilling to reveal the secret of his trick. For the previous month or so, Knox had been sending notes to Denniston about dealing with the French. The first problem was lunch:

  It has been a great pleasure to me, though somewhat testing to my knowledge of French, to bear-lead Captain B. from 8 a.m. to 10 p.m. I have taken the line, though he offered to pay generously, that entertainment is une affaire de bureau: that is, from my angle, that I should get a billeting allowance …7

  Then there were the niceties of dealing with the people. ‘Liaisons. Braquenié. Admirable. We are great friends …’ Knox had invited Henri Braquenié to stay at his house, which tested the limits of Braquenié’s admirability and friendship. ‘Dilly was no wine connoisseur and one can only wonder how the entente cordiale survived … even the odd admiral would be entertained with just a half-bottle of plonk.’8

  Denniston wanted the Polish experts for himself. It was understandably galling that Bertrand the bear had achieved his coup, but to punish him and Braquenié with peculiar versions of hospitality was perhaps unfair. But what was the explanation for the mysterious reappearance of the Polish code-breakers in his team?

  The ghastly train journey had, eventually, come to an end for Marian Rejewski, Jerzy Różycki and Henryk Zygalski.9 They switched to a truck after arriving at Brześć and then travelling became less dangerous, if no simpler. A week into their journey they reached Łuck (Lutsk). Here a deviation was ordered and they headed west again, towards the town of Włodzimierz (Volodymyr-Volynski). Just outside Włodzimierz is a tiny place then called Uściług. In 1939, the only thing this place was remotely famous for was that Igor Stravinsky had a house there; even today its population is microscopic. Possibly by reason of its remoteness, the intelligence officers stopped the convoy in Uściług. Kazimierz Gaca was one of the civilians employed in the Cipher Bureau, and, at 19 years old, the youngest of the code-breakers, but he also held a commission in the reserves. He was ordered out of the truck and told to dig a deep hole. It was a bit demeaning for an officer to be involved in grave-digging, but the saddest part was not the labour. To take the code-breaking secrets out of the country would be too dangerous, so into the hole went the fruits of years of intellectual sweat and all their precious kit: six bombas; Polish-designed Lacida cipher machines; unburnt papers; no fewer than seventy replica Enigmas; in fact, almost everything that had escaped the flames the week before.10 Then, back into the truck and back on the road south. On Sunday, 17 September 1939, they heard the news about the Russian invasion and the same evening they reached the border town of Kuty and crossed into Romania.

  Scores of refugees were on the road. The Romanian border guards were trying to separate military personnel from civilians: under the theory of neutrality, Polish military personnel were supposed to be interned. The military truck in which the code-breakers had bumped uncomfortably for hundreds of kilometres was ‘interned’, but in the chaos Rejewski, Różycki and Zygalski, not being uniformed members of the armed forces, blended into the crowd and quickly found their way to the railway station. The three arrived in Bucharest the next day. The others would have to fend for themselves.

  It was chaos in Bucharest too. The code-breakers decided to try the British Embassy. The French Army had proved itself unequal to the task of supporting Poland, or unwilling to try, but the British code-breakers seemed to have some real talent. Perhaps the best way to help Poland win back its independence would be to join the Br
itish war effort.

  Just as the three men arrived at the Embassy, a bus pulled into the yard. It disgorged a disorientated and stressed group of diplomats who had fled from Warsaw and made the long journey on the refugee-congested roads to Bucharest. The British Romanian mission was overwhelmed. Three civilian mathematicians, trying to communicate in German, trying to explain who they were without actually telling anyone anything, was a complicated, low-priority problem. They were told to come back the next day and meanwhile the British officials would try to contact London to check out their story, if time permitted.11