The Poles handed over to the British intelligence services a clone of the Enigma plugboard. The Poles had cracked an early version of Enigma as early as the early 1930s. French and British cryptanalysts had first arrived at Biuro Szyfrow’s headquarters in Poland. Szyfrow had been tasked years earlier with trying to crack Enigma. He had hired the country’s best mathematicians, including Marian Rejewski, who started by addressing some of its weaknesses: repetition is the enemy of security, for example. Repetition leads to patterns, which are a boon to cryptanalysts. For example, the Enigma key is encoded twice at the beginning of each message. By also analyzing the mechanical structure of the Enigma machine, he then managed to make the problem 10 billion times easier than it was initially. Then, using other “tricks,” such as partially decoded phrases that can be guessed, such as “alliveinbelrin” (arrive in Berlin), he adds the finishing touches. The Poles are thus able, by the early 1930s, not without a huge decoding effort, to decode the current version of Enigma (which, however, would later be made much more complex). When Hermann Göring visits Warsaw in 1934, he is completely unaware that his communications are clear to the Poles. When the French and British figure it out on July 24, 1939, they realize how far the Poles have come, already for almost a decade and with very limited funds, and they are astonished, especially the French. As a final surprise, the Poles offer them one of the two Enigma machines they have at their disposal. He will leave first for Paris and then for London on August 16th, among the luggage of the famous actress Yvonne Printemps, so as not to arouse suspicion among the German spies monitoring the ports. Two weeks later, World War II will begin, and cracking the Enigma code will make all the difference in the world…
