The Tunny Machine - The German Lorenz Cipher Machine Emulator During WW2

Описание: "The Lorenz SZ40, SZ42A and SZ42B (SZ for Schlüsselzusatz, meaning "cipher attachment") were German rotor cipher machines used by their Army during World War II. They implemented a Vernam stream cipher. British cryptographers, who referred to encrypted German teleprinter traffic as "Fish", dubbed the machine and its traffic "Tunny"."

"Originally the Tunny traffic was intercepted at the Foreign Office Y Station operated by the Metropolitan Police at Denmark Hill in Camberwell, London but due to lack of resource at this time (~1941) it was given a low priority. A new station, Knockholt in Kent, was later constructed specifically to receive Tunny traffic so that the messages could be efficiently recorded and sent to Bletchley Park. The head of Y station, Harold Kentwothy, moved to head up Knockholt. He was later promoted to head the Foreign Office Research and Development Establishment (F.O.R.D.E).

Several complex machines were built by the British to attack Tunny. The first was a family of machines known as "Heath Robinsons", which used several high-speed paper tapes, along with electronic logic circuitry, to find the pin wheel settings of the Lorenz machine.

The next was the Colossus, the world's first programmable electronic digital computer. This was developed by the British G.P.O engineer Tommy Flowers at Dollis Hill in London (the Post Office research station). Like ENIAC, it did not have a stored program, and was programmed through plugboards and jumper cables. It was both faster and more reliable than the Heath Robinsons; using it, the British were able to speed up the process of finding the Lorenz pin wheel settings.

The third machine was the Tunny Emulator. This machine was designed by Bletchley Park, based on the reverse engineering work done by Tiltman's team in the Testery, to emulate the Lorenz Cypher Machine. When the pin wheel settings were found by Colossus and manual cryptanalysis, the Tunny machine was set up and run so the messages could be read."