Throughout the war, the German military used the Enigma machine to encrypt their radio communications. They believed the code was unbreakable. However, a team of Allied codebreakers at Bletchley Park, led by mathematical genius Alan Turing, developed the 'Bombe'—an electromechanical device that could rapidly test Enigma settings. This intelligence, codenamed 'Ultra,' allowed the Allies to know German plans for U-boat attacks in the Atlantic and troop movements in Europe. Historians estimate that the work at Bletchley Park shortened the war by at least two years and saved countless lives. It also laid the foundational principles for modern computer science and artificial intelligence.