Lorenz SZ42 encrypting machine

In World War II, Hitler commissioned an encrypting machine that would be unbreakable. The Lorenz was used to encrypt teleprinter messages. Lorenz SZ40s were first used in June 1941, and the SZ42 from mid-1942 onwards.

The SZ42 had 12 wheels with different numbers of cams or pins that could produce 1.6 billion different combinations.

The Allies did not see a Lorenz machine until after the war but dubbed the machine and its messages "Tunny".

Enigma, an entirely different system, was used for operational messages and was much less complex.