French and Polish beat Enigma code

CLASSIFIED documents released by France for the first time have shown that France and Poland played a crucial part in cracking the Enigma code used by the Nazis – and disprove claims in the Oscar-winning Imitation Game film that it was all due to British mathematician Alan Turing.

Deciphering the Enigma code – which was used by the German army, air force and navy from 1932 to 1941 – enabled the Allies to intercept communications and played a key role in the eventual defeat of Nazi Germany in 1945.

French official ‘Mme Nathalie’ – whose real name has been withheld – of secret service archives department DGSE, said: “The situation portrayed in Imitation Game – that the French gave up trying to crack the Enigma code – is untrue.”

Proof of this is now available to the public after the DGSE decided to declassify some 600 documents connected to General Gustave Bertrand, the French intelligence officer who set up a department tasked with cracking military codes in 1930.

The “Bertrand archives” include references to a secret German source that reveals the major contribution made by France to deciphering the Enigma coding machine.

In 1931 General Bertrand was approached by a German agent who offered to sell information about messages being transmitted by his country. The French were also helped by Poland, which expressed fears that same year over “the development of Germany and its intentions” – three years before Hitler became Führer and consolidated his grip on power.

Historians assert that a Polish team of mathematicians led by Marian Rejewski in Warsaw was the first to understand that the German code was being produced by a mechanical system – like a very complex typewriter – which was subsequently perfected under the Nazi regime.

During the 1930s Rejewski and his colleagues, using material supplied by French intelligence from German sources, cracked Enigma repeatedly. But the Germans continued to use it, developing the code and making it increasingly difficult to decipher.

The Polish, French and British did not work together on Enigma until after Nazi Germany annexed Austria during the Anschluss of 1938. By then Polish intelligence had realised it did not have the resources to decipher increasingly complex German coding alone.

“The Polish undoubtedly brought good working methods with them – without them you would not have had the English [breakthrough],” said Olivier Forcade, expert on French intelligence during the Third Republic.

Forcade, who is also a history professor at the Sorbonne, added that he did not want to “diminish the genius of Turing”, but rather to set the historical record straight. “The Bertrand archives add the missing piece of the puzzle concerning the French intelligence services,” he said.