Secrets of World War II episode 7

 Secrets of World War II episode 7: By early 1940, British codebreakers at Bletchley Park, working with information from the Poles, had begun to crack the German military codes produced on the Enigma cipher machine. Once this had been achieved, the challenge was how to prevent the Germans from finding out their codes had been broken. It was transmitted on a top-secret device capable of scrambling a message millions of different ways.
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