<P> During the Second World War , Turing worked for the Government Code and Cypher School ( GC&CS ) at Bletchley Park , Britain 's codebreaking centre that produced Ultra intelligence . For a time he led Hut 8 , the section which was responsible for German naval cryptanalysis . Here he devised a number of techniques for speeding the breaking of German ciphers , including improvements to the pre-war Polish bombe method , an electromechanical machine that could find settings for the Enigma machine . Turing played a pivotal role in cracking intercepted coded messages that enabled the Allies to defeat the Nazis in many crucial engagements , including the Battle of the Atlantic , and in so doing helped win the war . Counterfactual history is difficult with respect to the effect Ultra intelligence had on the length of the war , but at the upper end it has been estimated that this work shortened the war in Europe by more than two years and saved over fourteen million lives . </P>
who cracked the enigma code in world war 2
Turing