This real story, researched by historian Dermot Turing, was a revelation. Turing provided an informed and engaging presentation which deftly over-turned previous myths of how the Enigma was broken. His opening remarks elicited loud gasps from the packed audience. For as early as 1932, Turing revealed, Polish mathematicians and engineers had already cracked Enigma codes. They’d created the ‘Bombe’ encryption device, which Alan Turing used to develop his own code-breaking machine. Dermot Turing, the nephew of Alan Turing, uncovered how this extraordinary collaboration took place between the Poles, the French underground and Bletchley Park – all under the noses of the Germans.
In the late 1930s, French Spymaster Gustave Bertrand got hold of a photo showing the latest German Enigma machine and its operating instructions. The British weren’t interested – they couldn’t make head nor tail of it – familiar only with the commercial form of the Enigma machine. So Bertrand brokered a deal with the Poles who’d get the information to decipher as long as they shared their results with the French. With Bertrand’s documents and intercepts of German messages, Polish mathematician Marian Rejewski used Group Theory to reconstruct the wiring, reverse engineering the German Enigma machine. He relied on guesswork to determine how the keyboard would differ from the commercial settings. His colleague Antoni Palluth was responsible for the ‘bombe’ encryption machine. Henryk Zygalski and Rejewski focussed on how the Germans set up the machines every day – without this knowledge, there could be millions of permutations. All this had been achieved by 1938, however Gwido Langer, the head of the Polish code-breaking service didn’t keep the Polish side of the bargain to provide this back to Bertrand.
In the late 1930s, the British started talking to the French about the Germans. They were hesitant initially about talking to the Poles, but Bertrand set up a meeting in July 1939 between MI6, the French and Polish intelligence. An intelligence triangle was set up: X – Paris, Y – British, Z – Poles.
The 1939 German invasion of Lithuania made the Polish codebreakers realise that nothing was safe. Two new rotors were added to the German Enigma machine, so now there were sixty new combinations instead of six. The Poles didn’t have the engineering capacity to address this higher order of complexity, but the British did. The XYZ triangle convened in Warsaw and the British were shown the Polish secrets. The Brits returned with briefcases full of know-how about die Zylgometer (‘the Enigma’) and die Bomben (‘the bombs’), going from zero to complete knowledge about the Enigma in July 1939 – five weeks before the invasion of Poland.
Alan Turing’s design was with British engineers before Christmas 1939, and first results started to show in time for the Battle of Britain in 1940. The Polish codebreakers escaped from Poland to France and were recruited by Bertrand and continued their collaboration with a teleprinter linked to Bletchley Park. When the Germans invaded France, both the Poles and the French intelligence escaped to North Africa and ended up in the South of France. In this paranoid environment, where everyone was watching everyone else, Bertrand persuaded the Vichy government to fund an intelligence agency that only spied on the Germans. He argued successfully that it was too difficult technically to check up on the British.
Life in the code breaking station was pleasant – romances were struck up and there was time for tennis and cycling. Then the Germans invaded the South of France and, in late October 1942, the codebreakers started to appear on wanted posters. As the Poles were using the site as a relay station to London, documents and machines were destroyed before they fled. Some escaped to Britain and reported to Polish military intelligence.
The fates of other codebreakers were mixed. Palluth was captured by the Germans and murdered. Langer made it to England but couldn’t get a proper job – unable to tell anyone he’d been in Polish intelligence he died in 1947. Zygalski had a happier fate: he became a mathematics lecturer, fell in love and made Britain his home. The codebreakers group as a whole were fearful of Soviet retribution, if they returned to Poland. Rejweski was the only one brave enough to go back. Fortunately for him, it was the Polish secret service that had him under investigation. He got a job in an Accounts department and eventually was able to convince local agents that he was no more than a boring accountant.
Without the heroism, courage and genius of the Polish code-breakers ‘Bletchley Park’s achievements might never have happened’. More about their story can be found in Dermot Turing’s lively and accessible book XY&Z – The real story how Enigma was broken (The History Press, 2018).
about the Enigma: http://enigma.umww.pl/en/
about the author Dermot Turing: https://dermotturing.com