Denis Oswald (cryptanalyst)

Denis G. Oswald (* around 1910; † after 1973) was a British cryptanalyst , linguist and officer. During the Second World War he worked in the Government Code and Cypher School (GC&CS) (German: "Staatliche Code- und Chiffrenschule") in Bletchley Park (BP), the military service that successfully deciphered German communications concerned.

Life

The mansion (Engl .: The mansion ) of Bletchley Park (2002) was the headquarters of the British code breaker and is now a museum

Major Denis Oswald ran from the summer of 1941 to 1942 the Mansion (see picture), the old mansion and the central building of BP, a small group of code breakers that on the deciphering of double box wrenches (English name:. Double Playfair ) worked as time were used as a manual key procedure by the German police .

In the same year he joined the Testery , which was created on July 1, 1942, as one of the four founding members (senior cryptographers) , all of whom spoke fluent German . Under the direction of Ralph Tester and together with Jerry Roberts and Peter Ericsson , the German Lorenz key machine was broken there . The Wehrmacht used this highly complex key machine (own name: Schlüsselzusatz 42 ; short: SZ 42) to encrypt their strategic telex connections , in particular between the Wehrmacht High Command based in Wünsdorf near Berlin and the army headquarters in cities such as Rome, Paris, Athens, Copenhagen, Oslo , Königsberg, Riga, Belgrade, Bucharest and Tunis. The British gave him the code name Tunny ("tuna").

Denis Oswald successfully continued this task in Europe until the end of the war . The number of staff at Testery had meanwhile increased to 118 employees.

After the war he worked for many years until 1974, including as a language teacher at the Uppingham School in Uppingham , a community in the East Midlands region of England , without anyone there knowing anything about his earlier work that was important to the war effort. He died without having been recognized for his services during his lifetime.

In contrast to the deciphering of the Enigma machine , which was guarded until the 1970s ( Britain's best kept secret ), the successful break of the Lorenz machine was an even bigger secret. Many years after the war, around 2012, one of his former colleagues at BP, Jerry Roberts (1920–2014) , who was then 90 years old, recalled :

"Yes, Denis Oswald was working with me at Bletchley, he was a very good person, one of the best cryptographers in the Testery, a pipesmoker, always very well groomed."

"Yes, Denis Oswald worked with me in Bletchley, he was a very good person, one of the best cryptologists in the Testery , a pipe smoker, always very well-groomed."

- Jerry Roberts

Web links

• Major Denis Oswald article in Old Uppinghamian (OU) with photo by Denis Oswald, 2012/13, p. 28, (English). Retrieved January 23, 2017.
• Denis Oswald in the BP Roll of Honor (English). Retrieved January 23, 2017.
• The Testery Description (English) as well as historical photos (from the 1980s) of the Testery . Retrieved January 23, 2017.

Individual evidence

1. ↑ Major Denis Oswald article in Old Uppinghamian (OU) with photo by Denis Oswald, 2012/13, p. 28, (English). Retrieved January 23, 2017.
2. ^ Gordon Welchman: The Hut Six Story - Breaking the Enigma Codes . Allen Lane, London 1982; Cleobury Mortimer M&M, Baldwin Shropshire 2000, p. 11. ISBN 0-947712-34-8
3. ^ BP Roll of Honor (English). Retrieved January 23, 2017.
4. ↑ The Testery (English). Retrieved January 23, 2017.
5. ^ Donald Michie : Colossus and the Breaking of the Wartime "Fish" Codes . Cryptologia , 26: 1, pp. 17-58, 2002. doi: 10.1080 / 0161-110291890740 . DOC; 220 kB .
6. ↑ Ted Enever: Britain's Best Kept Secret - Ultra's Base at Bletchley Park . Sutton Publishing Ltd, January 1994. ISBN 0-7509-2355-5 .
7. ↑ Major Denis Oswald article in Old Uppinghamian (OU), 2012/13, p. 28, (English). Retrieved January 23, 2017.