- For the (Fibonacci Shrinking) stream cipher published in 1993, see FISH (cipher).
Fish (sometimes FISH) was the Allied codename for any of several German teleprinter stream ciphers used during World War II[1][2][3]. While a large number of links were monitored, at least three different encryption systems were distinguished:
- Tunny — the Lorenz SZ 40 and SZ 42 from Lorenz Electric. Tunny traffic was read successfully at Bletchley Park, using the famous Colossus computer. Paul Gannon's book Colossus: Bletchley Park's Greatest Secret[4] gives a detailed description of the interception of German military wireless traffic using teleprinter code (often referred to as non-morse traffic to distinquish it from the Enigma traffic) by Knockholt Intercept Station, the recording of those signals, the identification of the type of codes in use, the breaking of the codes using advanced statistical and cryptographic techniques, the development of mechanical, electro-mechanical and electronic machines (including the development of Colossus computer) to aid the decryption and an appreciation of the value of the intelligence gained.
- Sturgeon — the Siemens and Halske T52 from Siemens. Although Bletchley Park managed to work out Sturgeon, they never read much of its traffic.
- Thrasher — probably the Siemens T43 one-time tape machine. The T43 was used only on a few circuits, in the later stages of the war.
See also: Ultra
References
- ^ Wolfgang W. Mache, Geheimschreiber (Cryptology: Yesterday, Today and Tomorrow, Artech House, Norwood, 1987)
- ^ Cipher A. Deavours and Louis Kruh, Mechanics of the German Telecipher Machine (also reprinted in Cryptology: Yesterday, Today and Tomorrow)
- ^ Wolfgang W. Mache, The Siemens Cipher Teletype in the History of Telecommunications (reprinted in Selections from Cryptologia: History, People, and Technology, Artech House, Norwood, 1998)
- ^ Paul Gannon, Colossus: Bletchley Park's Greatest Secret, Atlantic Books, London, 2006
