wikiepadia.org: "The Lorenz SZ40, SZ42A and SZ42B were German rotor stream cipher machines used by the German Army during World War II. They were developed by C. Lorenz AG in Berlin and the model name SZ was derived from Schlüsselzusatz, meaning cipher attachment. The instruments implemented a Vernam stream cipher. British cryptographers, who referred to encrypted German teleprinter traffic as Fish, dubbed the machine and its traffic Tunny. Some messages were deciphered using hand methods before the process was partially automated, first with Robinson machines and then with the Colossus computers." Read on
