How did the British crack enigma?

Answer 1

There is not a short or simple answer to this question. Several books have been written about British efforts to penetrate the German Enigma Codes during the Second World War. It began with the Polish government efforts in the months prior to the German invasion of Poland in September 1939. The Poles used several brilliant mathematicians working long hours to start. The British used mathematicians, early computers-like machines, and British made replicas of the Enigma cipher machines. It also required a very large number of Enigma coded radio transmissions that were intercepted (heard), recorded, and catalogued by the British. The idea was to discover a few letters or numbers that were encoded. To build on that knowledge to discover words & phrases, and then eventually sentences. The Enigma code actually changed often over the course of weeks. The British had to create a working machine that could accept all the identical changes (settings) made on the German machines and determine when & how to make the changed settings at the same time as the Germans. This took months & years of work. Sometimes a German Enigma machine or code book was captured that helped in the research. Sometimes the code was read for only a short time until the Germans changed the code (turned rotors & rearranged cable plugs) in their machines in a way that the British could not quickly duplicate. The code never stayed "cracked" and often only portions of German messages were decoded. It is a very complicated business, so often the most difficult mind-work ever done. Modern computers help a lot, but modern codes also use codes created by computers. Both sides use technology.

Answer 2

The Enigma code was cracked by British code breakers led by Alan Turing at Bletchley Park, a secret establishment in WW2. There is a TV series about it as well as a recent movie, The Imitation Game.

Answer 3

It was cracked by the brilliant mathematician Alan Turing and his team at Bletchley Park.