Gardening (cryptology)

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As gardening ( German  literally: gardening or gardening ), occasionally also as Operation Garden , (not to be confused with the Operation Garden of the same name as part of the allied air-to-ground operation Market Garden of 1944) was used in cryptology , especially in the Cryptanalysis of the rotor key machine Enigma used by the German military during the Second World War , a process that was intended to trick the German side into sending ciphertexts for which the British codebreakers in Bletchley Park (BP) in England guessed the corresponding plaintext could. This served them as a crib for the intercepted radio messages and helped them successfully decipher the German machine.

Procedure

The British deliberately provoked incidents just to receive the expected German radio messages with known content and encrypted with the current day code. The British code breaker Rolf Noskwith from Barrack 8 ( Hut Eight ) of BP described them as follows: “The RAF dropped mines at certain points in the North Sea, so that the German mine warning served as a crib. The digits were carefully selected to avoid certain digits, such as 0 and 5 in particular, [as coordinates] for which the Germans used different letters. ”The British were able to avoid the distinction between“ NULL ”and“ NUL ”. as well as "FUENF" and "FUNF", which make work a little easier. Except in the case of “ZWEI” and “ ZWO ” there was only one spelling for the remaining digits. Also deciphered messages of smaller naval units, such as harbor vessels which did not have the Enigma and instead hand key method ( shipyard key or reserve hand method used), served the British as Cribs in breaking the Enigma. The Germans sent many radio messages, such as mine warnings, verbatim both as Enigma ciphertexts and encrypted using the manual method. The British were grateful for these “ciphertext-ciphertext compromises” and called them Kisses .

Origin of the term

The term gardening originally means “ horticulture ” or “gardening”. It was then adopted by the pilots of the Royal Air Force as a jargon term for the dropping of sea ​​mines in rivers, ports or sea areas from low altitudes. One reason for this choice of term was possibly that the British had given the sea areas around the European coasts code names after various flower names and vegetables . The cryptanalysts at BP finally use this catchy name for their deciphering method , which was based on the “gardening” of the RAF.

literature

Web links

Individual evidence

  1. ^ Hugh Sebag-Montefiore: Enigma - The battle for the code . Cassell Military Paperbacks, London 2004, p. 215. ISBN 0-304-36662-5 .
  2. ↑ a b Michael Smith: Enigma decrypted - The "Codebreakers" from Bletchley Park . Heyne, 2000, p. 107. ISBN 3-453-17285-X .
  3. ↑ a b Christopher Morris: Navy Ultra's Poor Relations in Francis Harry Hinsley, Alan Stripp: Codebreakers - The inside story of Bletchley Park . Oxford University Press, Reading, Berkshire 1993, p. 235. ISBN 0-19-280132-5 .
  4. ^ 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
  5. ↑ Friedrich L. Bauer: Deciphered secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin et al. 2000, p. 400.
  6. ↑ Glossary of WWII RAF Slang & Terminology (English). Retrieved June 20, 2016.