Alan Turing
Warsaw Meeting
Warsaw, Poland
After the July 1939 Warsaw meeting at which the Polish Cipher Bureau had provided the British and French with the details of the wiring of Enigma rotors and their method of decrypting Enigma code messages, Turing and Knox started to work on a less fragile approach to the problem. Their approach was more general, using crib-based decryption for which he produced the functional specification of the bombe (an improvement of the Polish Bomba).