X, Y & Z

by Dermot Turing

  But time was running out. If the Romanian security police found out who the code-breakers were, there was every chance they would be handed straight over to the Gestapo. Waiting even twenty-four hours was a very unattractive option. They would have to try the perfidious French, even though that nation had abandoned its feeble invasion of Germany.

  The French Embassy was calm and bureaucratic, but the Poles knew the key to this particular diplomatic lock. Years of liaison with Bertrand meant that simply mentioning the name ‘Bolek’ – the code word for Bertrand known to the Deuxième Bureau – opened the way. A quick check back with Paris assured the fugitives every support: passports in false names and visas to go with them would be provided right away, together with special additional documentation essential for the three to get to France. Maybe, after all, the French were not quite as perfidious as it had seemed.

  After two days the three mathematicians left the French Embassy. Despite all the preparations there was an initial hitch: the Romanians were not convinced about their permit to travel. Here the French officials’ familiarity with Romanian procedure came to the rescue: the special additional documentation, slipped in between the regular papers, consisted of a 500-lei note. It seemed there might not be a problem with the code-breakers’ departure after all. Finally, they were on their way to France. The long journey by train took over three days, via Yugoslavia and Italy. At the French-Italian border there were more problems. At Modane, on the French side, a clearing centre had been set up. A new army was being formed out of the wreckage of the flight from Poland, under the charismatic leadership of General Władysław Sikorski. The post-Piłsudski government had collapsed along with the failed defence of Poland. Sikorski was ideally placed to take control: with a strong war record from the Russo-Polish conflict of 1920, and some experience of government, he had briefly served in government but latterly had been the leading figure in the opposition. Now Sikorski was trying to extricate as many men from Poland and Romania as possible to continue the fight. The three code-breakers were going to have to wait while the Franco-Polish officers worked out who was who.

  Then another of Bertrand’s magical moments occurred. A French officer appeared. There was no need for the three gentlemen with the fake IDs to wait in line. They were expected. Perhaps they would care to come this way. The French officer took them straight back to the station and, without further fuss, they were on their way to Paris.

  Meanwhile, Bertrand was trying to get hold of Langer and the rest of his team. Having been separated from the civilians at the Romanian border, the uniformed members of the Cipher Bureau were due to be interned. Internment in Romania, however, in the boiling political climate of September 1939 was not the measured and orderly process taking place in Britain (where assorted foreigners and suspected spies were being rounded up). Romania was the very opposite of measured and orderly. A dictatorship had been in place for a year, but this did not guarantee security. The prime minister was assassinated in the middle of the Polish crisis. Tens of thousands of Polish servicemen had flooded across the border. There was nowhere for the ‘internees’ to go and the Romanians did not want them to stay. But getting out was easier for some than others. The young Kazimierz Gaca, who was carrying the only AVA-made duplicate Enigma machine to survive the burial at Uściług, wangled his way on via Yugoslavia to Greece, eventually boarding a ship in Piraeus bound for Marseilles. His journey took five months.12

  When Warsaw surrendered on 27 September 1939, Gwido Langer found himself in Calimanesti in the heart of the Romanian countryside. A French Army officer appeared, clutching a telegram containing an invitation in the name of Colonel Louis Rivet, for Langer, his colleagues and their families to join Bertrand’s unit in Paris. Langer’s boss, Colonel Stefan Mayer, was also at Calimanesti and approved the move.13 Within four days the entire group was relocated to Paris and reunited. There, in the suburbs, where peacetime frivolities still prevailed, the Polish code-breakers could carry on the intelligence struggle.

  • • •

  As the autumn of 1939 greyed into winter, a spirit of optimism seemed to infuse the British at Bletchley Park. A tea-stained note in the British National Archives begins with an optimistic, ‘we may with some hope look forward to the state when we shall be able to deal with some of the German Enigma traffic.’14 And on the same day, Bertrand wrote to Denniston to arrange another three-way meeting. Now the secret of his capture of the Poles was out, Bertrand was ready to revive the X-Y-Z liaison properly. Queries, intercepts and ideas were flowing back and forth again, as was a seasonal spirit of goodwill. ‘My dear Bertrand,’ wrote Denniston on 23 December 1939, ‘I am writing to wish you a very restful (?) Christmas and, I hope, a prosperous 1940, which year may, I trust, be the last for the Nazi Band.’15 The spirit of Christmas optimism could not go much higher than that. Outside, the winter of 1939–40 was turning into the coldest for forty-five years. When the ornamental lake at Bletchley Park froze over, some of the code-breakers gingerly ventured out wearing skates. Although the entente cordiale was providing some degree of warmth, the fundamental problem of finding a way to uncover the Enigma keys in real time had not been solved. Poland was still ripped in two and it was far too early to predict the demise of the Nazis.

  For, on 14 December 1939, Adolf Hitler had given orders to prepare another invasion, this time in the West.

  7

  THE MIRROR CRACK’D FROM SIDE TO SIDE

  Out flew the web and floated wide;

  The mirror crack’d from side to side;

  ‘The curse is come upon me,’ cried

  The Lady of Shalott.

  Alfred, Lord Tennyson

  ‘The Lady of Shalott’

  The Battle of Poland was over. The British and the French found themselves in a ‘phoney war’. The French called it the ‘drôle de guerre’. And against the background of an imminent threat of real war, a diplomatic battle was underway between X and Y.

  To win the war against the Germans, it was self-evident that the Polish cryptologists should join the Y team at Bletchley Park. On 10 October 1939, MI5 had been ‘asked to receive seventeen Polish cryptographers who are said to be experts in Russian and German ciphers. We have said that we will be guided by the Government Code & Cipher School. I gather, however, that they do not want all these people and would much prefer to see them in France. Alastair Denniston has already had a talk with them in Warsaw … they might be very useful.’1 The idea of the Poles moving to Bletchley was suggested to Gustave Bertrand on 29 December, but ‘the French Government were paying for the Polish Army and therefore the Poles must work in France’. A weak excuse; it was time to try again.

  Dear Menzies,

  Here are the names of the three young Poles, Jerzy Rozycki, Marian Rejewoli [sic], Henryk Zygalski. If we are faced with a change on the outbreak of War (and we begin to suspect it), the experience of these men may shorten our task by months. We possess certain mechanical devices which cannot be transferred to France. These young men possess ten years’ experience and a short visit from them might prove of very great value.

  Yours ever sincerely, A. G. Denniston.2

  It seemed that Bletchley Park was losing this battle. Come what may, Bertrand was not going to agree to a transfer of his star players. ‘I am resigned,’ wrote Alastair Denniston to Bertrand on 7 February 1940, ‘to not receiving the Zs with us. You have said frankly that it is impossible, so I accept it.’3 Alastair Denniston was unfailingly polite. When decrypted, the message meant that he did not accept it, but his hand had been forced. Perhaps it was not too intolerable. With a teleprinter link between Bertrand and Bletchley, cooperative relations could still go on. France, where the X and Z teams were playing, was not so far away, and Y had some star players of its own, whose scoring abilities were just becoming recognised. One of them was Alan Turing.

  Alan Turing was not regarded as being much good at German. At one stage – when he was learning German at school – this would have been considered
a fatal flaw in a code-breaker whose job was to decrypt German messages. In 1931, Turing’s German teacher had said, ‘he does not seem to have any aptitude for languages’.4 By 1940, though, the schoolmaster might have had to revise his opinion, since the study of mathematics at a higher level in the 1930s obliged go-ahead students to master the German language. And Turing was also competent in French: his mother (a fluent French speaker who had herself studied in Paris and lived in France for several years) had force-fed him on French in earlier years. So, after the frozen Christmas of 1939, Alan Turing was selected for a multilingual international mission.

  During 1938, while the bombas were still being developed, Henryk Zygalski had invented a new technique to exploit ‘females’ (repeated letters showing up in the indicator which the Germans transmitted at the start of a message) to find out the set-up of the German Enigma machines. The new approach used perforated cardboard sheets. Zygalski’s idea was to represent the configurations of Enigma rotors on sheets of card ruled into a grid, with the vertical axis listing all positions of the right-hand rotor and the horizontal one all positions of the middle rotor. In this way, twenty-six sheets would do for all possible positions of three rotors. Then holes were punched into the sheets in positions where females were possible. When the sheets were ready, they could be stacked on a light-table, and the correct choice of rotors and their start position would be revealed by a single ray of light shining up through the holes in the stack.*

  The sheets were tedious to create, complex to use, and relied on a manual process which seemed less sophisticated and more time-consuming than the modern, electric bombas. But the beauty of the Zygalski sheets was that the theory removed the plugboard from contention altogether. For the sheets to work it didn’t matter how many annoying cross-pluggings the Germans were using. So long as the Germans continued to encipher the three-letter indicator sequence twice over, there would be a copious supply of females and the need for machinery was postponed.

  That was 1938, but with the advent of the Germans adding two rotors, so that there were five to choose from, 1,560 cardboard sheets were now needed. The Polish team had been cutting out holes from their sheets with razor blades. With around 800 holes per sheet, it was a tedious and time-consuming job. The British, however, were working on their own set and ordered a punching machine to do the task. When it arrived, it drove Alan Turing into the attic to escape the noise.5

  Soon after Christmas 1939, the punching of the cardboard sheets was done. Thus, Alan Turing was detailed to take a set across to France, though not before Knox had lost his temper and threatened to resign unless the sheets were made available to the allies. (‘Unless they leave by Wednesday night I shall tender my resignation. I do not want to go to Paris but if you cannot secure another messenger I am actually at the moment completely idle.’6) Having disparaged the Poles once, now he had the zeal of the convert. But Denniston was going to act cautiously. The choice of Turing for the mission may have been only slightly more cautious, given Turing’s well-known eccentricities and social awkwardness, but they needed to send someone who was fully on top of the technical side.

  For the Enigma team at Bletchley Park were facing some more puzzles which the intelligence from Pyry did not seem to solve. First of all, the splendid cardboard sheets were slow and inefficient to use. And on top of that there was a problem with Method Kx. Method Kx was a technique for inspired guesses at rotor-orders, which exploited ‘Cillies’ – the inability of humans to pick three letters at random, so allowing code-breakers to guess that the starting positions chosen by German operators were such ‘random’ sequences as AAA or QWE or SOS. But Method Kx didn’t seem to work when the two new rotors, introduced by the Wehrmacht in December 1938, were involved.7 Alan Turing, who understood these problems, would go to France, his school reports notwithstanding.

  Marian Rejewski may not have known about Turing’s 1936 paper on Computable Numbers, which turned the theory of mathematics upside-down and at the same time introduced a model for a programmable computer. And Turing was not Knox; he was an unknown in the Bletchley Park equation. So Rejewski may be forgiven for being slightly patronising: ‘we treated Turing as a younger colleague who had specialised in mathematical logic and was just starting out in cryptology.’8 It may have been just the way to deal with Turing; the meeting was a roaring success. Using the freshly minted Zygalski sheets, the Poles in exile showed Turing (using intercepts dating from the previous October) how to stack them up in the most efficient way and to find the rotor-settings and plugboard connections. On 17 January 1940, eleven weeks after their transmission, the first Enigma messages of the war were read by the Poles, the French, and Turing, the emissary from Britain. It was a result at last for X-Y-Z. And a further big plus for Turing’s mission was that the problem of the Method Kx was solved. There had been a misunderstanding over the position of the turnover notch on the new rotors.

  A celebration was in order. Bertrand and Langer hosted a dinner at a nearby restaurant. On the table was a small glass vase containing a few autumn crocuses. Flowers in a freezing January are a rarity and Langer pointed to them, giving their Polish and German names. Then, observing Turing’s incomprehension, Jerzy Różycki chipped in, in Latin. Colchicum autumnale. ‘Why! That’s a powerful poison!’ exclaimed Alan Turing. Alan Turing’s life would end, fourteen years after that dinner, with a dose of an even more powerful poison.

  • • •

  In 1940, a whiff of poison was in the air, not for Alan Turing, but for the more senior members of the exiled Polish intelligence service including Maksymilian Ciężki and Antoni Palluth. The new government of Władysław Sikorski was investigating just what had gone wrong the previous autumn to allow Germany to make such a successful assault on Poland.

  Professor Stanisław Kot, leading member of the Peasants’ Party in Sikorski’s government-in-exile, was minister of ‘internal affairs’ (which was slightly odd, since the ability of Sikorski, Kot, or anyone else to do much about the internal affairs in their torn country was somewhat limited). Perhaps for that reason it was Kot who went to a series of liaison meetings that took place with the British Foreign Office. It was at these meetings – for which the British wheeled out of retirement their favourite Polish expert, Professor Lewis Namier, erstwhile author of the Curzon Line –that the Foreign Office learned about the poisonous atmosphere among the Polish émigrés. On 9 November 1940, as the professors sipped their tea, Kot revealed that matters were not entirely harmonious in the State of Poland. In particular, the relations between the Polish government’s undercover resistance organisation and its intelligence bureau were at a low point. The bureau was staffed with old-timers from the Sanacja régime, whose leader was Edward Rydz-Śmigły. Sanacja itself was being cleaned up, with a new head of Polish military intelligence, Colonel Stanisław Gano, due to take over.

  Blame needed to be allocated. While most of the blame must rest with the unloved régime of Rydz-Śmigły, the dirt might extend deep into the army’s substructure and its aristocratic officers. There was, it seemed, a good deal to investigate.

  The investigator was Lieutenant Colonel Ludwik Sadowski and his brief was wide-ranging.9 He was to name names and point fingers. He was to identify the men who should have assessed the plans of the enemy. What were the political affiliations of these men? Why did the intelligence service fail to act with agility upon the invasion? Why were budgets misspent? The Second Department of the General Staff was responsible for intelligence. The Biuro Szyfrów was part of the Second Department and there was an unpleasant contrast between the total failure of intelligence during the Battle of Poland and the Biuro’s achievements with Enigma during the years of peace. This was exactly the pattern you’d expect if there were a German influence at work in the Biuro. Statements were taken, from Ciężki, from Palluth, from those employed at Pyry and elsewhere.

  As for the budgetary investigation, wasn’t it clear that the Biuro Szyfrów had needed more code-breakers? And an effic
ient system of bringing results to the command? Whereas, in fact, the money had been spent on a ludicrous radio tower which could not even relay signals to the army commanders. The mismanagement went even further: the tower had been blown up prematurely and the explanation for this seemed to be that Maksymilian Ciężki had been receiving kickbacks from Antoni Palluth’s AVA company and these two had destroyed the tower as part of a scheme to cover their tracks. Self-evidently their relationship was altogether too cosy. Palluth and Ciężki said that that was nonsense, but of course they would say that. What was needed was more evidence.

  Actually, what was needed was a blast of cold, common sense. Major Wiktor Michałowski gave his deposition to Sadowski’s inquiry on 14 December 1939. Of course, there had been some leadership failures within the Biuro after the war broke out, but frequent relocations and a constant division of resources had hampered the code-breakers’ efforts. Moreover, there was a shortage of intercepted material to work with and they had been constantly harried by the Luftwaffe. In the final analysis, Sadowski had Ciężki and Palluth in his sights for a political reason rather than a genuine concern that corruption or German influence had undermined the efficacy of the the Biuro. The cloud over Ciężki and Palluth was that since the fighting in Poland had ended, the Biuro’s leaders and their staff had been working not for General Sikorski, but for the French.

  • • •

  While the unpleasant business of the post-mortem was going on, Team Z were settling into their new quarters. On 20 January 1940, just after the meeting with Alan Turing, the X and Z groups moved into the Château de Vignolles.10 The château was an attractive country house with rather nice grounds in a village called Gretz-Armainvilliers, situated near enough to, but outside, Paris. The out-station was called ‘Poste de Commandement Bruno’, or PC Bruno for short. The garden was infested with rabbits. Bertrand designed a special letterhead for the secret out-station, with gambolling bunnies as a logo and the address unhelpfully specified as ‘Somewhere in France’; whether this increased the credibility of his reports is not revealed.11