German code breaking in World War II German code breaking in World War II German code breaking in World War II achieved some notable successes cracking British Naval ciphers until well into the fourth year of the war, but also suffered from a problem typical of the German armed forces of the time: numerous branches and institutions maintained their own cryptographic departments, working on their own without collaboration or sharing results with equivalent units. This led to duplicated effort, to a fragmentation of potential, and to lower efficiency than might have been achieved. There was no central German cryptography agency comparable to the British Bletchley Park facility.
Rotor machine Rotor machine In cryptography, a rotor machine is an electro-mechanical stream cipher device used for encrypting and decrypting secret messages. Rotor machines were the cryptographic state-of-the-art for a prominent period of history; they were in widespread use in the 1920s–1970s. The most famous example is the German Enigma machine, whose messages were deciphered by the Allies during World War II, producing intelligence code-named "Ultra". The primary component is a set of "rotors", also termed "wheels" or "drums", which are rotating disks with an array of electrical contacts on either side. The wiring between the contacts implements a fixed substitution of