How Alan Turing and His Fellow Codebreakers Broke the Nazis’ “Unbreakable” Enigma Code

There was a time when you could just go out and buy an Enigma machine. In the early nineteen-twenties, any organization with a need to keep its communications secret could order a few of those brand-new devices from Germany and rest assured that any messages encoded using them would be safe from prying eyes. It didn’t take long for the military to catch on to the Enigma’s usefulness. Just a few years after the machine came on the market, it had been adopted by the German Navy, Army,