Alan Turing's Obscure Contributions

Most people know Alan Turing cracked Enigma. Fewer know he also designed a voice encryption device for Churchill's transatlantic phone calls to Roosevelt called 'Delilah.' It used mathematical scrambling rather than physical key rotation and was never deployed because by the time it was perfected, transatlantic cable encryption was sufficient. Turing also worked on the bombe machine's later versions, which could break the even more complex naval Enigma used by German U-boats. His work specifically helped end the Battle of the Atlantic, where U-boats were sinking 60+ ships per month.