T 52b telegraphic cipher machine, given the code name "Sturgeon" by the Allies

The Geheimschreiber (secret teleprinter) was used in World War II at the command level of the German Navy and Air Force. The T52b encrypts the 5-bit Baudot code of the teleprinter. The 10 reels are moved irregularly and generate pseudo-random numbers, which are cleared by the plaintext. A scrambler circuit then swaps the 5 encrypted bits around. The T52b was cracked in 1940 by Swedish cryptologists; the British codebreakers only partially succeeded.