Dennis Babbage

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The legendary Hut 6 was Dennis Babbage's primary workplace in Bletchley Park

Dennis William Babbage (born April 26, 1909 , † June 9, 1991 in Cambridge ) was a British mathematician and cryptanalyst . 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. There he contributed significantly to the breakage of the German ENIGMA key rotor machine .

For the failure of the German encryptor, as saying key the basic position to choose, he coined the nickname "JABJAB" .

Bletchley Park

During the first few months, Dennis Babbage worked in this building (English: The Cottage ) together with Dilly Knox on the deciphering of the ENIGMA

Dennis Babbage studied at Magdalene College in Cambridge from 1927 and came as an active army officer to Bletchley, 70 km north-west of London , shortly after the first Christmas of the war (in 1939) . He first worked for some time with Dillwyn "Dilly" Knox in the so-called "cottage" (a small country house on the premises of BP) before he became one of the first "magicians" (originally called "wizards" ) to crack the code in 1940 von Hut 6 (German: Baracke 6), i.e. the newly founded organizational unit of BP, which, under the direction of Gordon Welchman and his deputy Conel Hugh O'Donel Alexander , deciphered the information from the German Army and Air Force with the ENIGMA I. should deal with encrypted radio messages. He advanced to become one of the leading minds in the local cryptanalytic "engine room" and became the recognized expert on the methods for breaking ENIGMA keys on a daily basis. Together with Hugh Alexander and Stuart Milner-Barry , he was part of Gordon Welchman's "management team" .

At the beginning of 1940, BP was still far from being able to routinely “ crack ” German radio messages . In particular, there was hardly any machine support for the British “codebreakers” , as it was only later available in the form of the electromechanical “cracking machine”, the so-called “ bomb ” , devised by Alan Turing and further improved by Gordon Welchman .

One of the most important sources at that time was a key network operated by the German Air Force , which the British code breakers had given the code name "Red" (German: Rot). By deciphering the radio messages from this key network, the British obtained important information about pending air raids aimed at destroying the British RAF and achieving German air supremacy over England ( “Battle of Britain” ). This was considered a prerequisite for the planned invasion of England by the Wehrmacht in September 1940 under the code name " Operation Sea Lion ".

ENIGMA radio message intercepted in Bletchley Park (Part two of a three-part message)

In the summer of 1940 there were still no operational "bombs" and the cryptanalysts were forced to use manual methods to break the German radio messages. The procedures were extremely tedious, slow, and error-prone. One of the broken radio messages reported that the Germans were planning to use a new reverse cylinder (VHF) instead of the usual VHF B in the ENIGMA. The British code breakers had already given her the onomatopoeic nickname "Uncle Walter" (German: "Onkel Walter"). During the late shift on one of those summer evenings, had received Dennis Babbage as head of the film, a very long multi-part radio message that seemed indecipherable, though using the spell head clearly identified as a key county "Red" was recognized as belonging. By breaking further radio messages, the daily key was already known, which the Germans changed at midnight and which remained valid for a whole day within a key network. Babbage examined the headers of all parts of the radio message, identified the sender and guessed - as it turned out a little later, completely correctly - the secret roller start position of the messages chosen by the sender. This subsequently led not only to the deciphering of the radio message, but, more importantly, to identify and complete reconstruction of the hitherto unknown wiring of the new FM C .

After the war, Dennis Babbage worked as a professor of mathematics at Cambridge University . For his services in World War II, he was inducted into the Order of the British Empire (MBE).

literature

Web links

Individual evidence

  1. ^ 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
  2. ^ Gordon Welchman: The Hut Six Story - Breaking the Enigma Codes . Allen Lane, London 1982; Cleobury Mortimer M&M, Baldwin Shropshire 2000, p. 102. ISBN 0-947712-34-8
  3. ↑ Friedrich L. Bauer: Deciphered secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin et al. 2000, p. 426.
  4. ^ Gordon Welchman: The Hut Six Story - Breaking the Enigma Codes . Allen Lane, London 1982; Cleobury Mortimer M&M, Baldwin Shropshire 2000, p. 35. ISBN 0-947712-34-8
  5. ↑ Michael Smith: ENIGMA decrypted - The "Codebreakers" from Bletchley Park . Heyne, 2000, p. 59. ISBN 3-453-17285-X
  6. ^ Hugh Sebag-Montefiore: ENIGMA - The battle for the code . Cassell Military Paperbacks, London 2004, p. 90. ISBN 0-304-36662-5
  7. ^ Gordon Welchman: The Hut Six Story - Breaking the Enigma Codes . Allen Lane, London 1982; Cleobury Mortimer M&M, Baldwin Shropshire 2000, p. 127. ISBN 0-947712-34-8
  8. ^ Rudolf Kippenhahn: Encrypted messages, secret writing, Enigma and chip card . Rowohlt, Reinbek bei Hamburg 1999, p. 244. ISBN 3-499-60807-3
  9. ↑ Simon Singh: Secret Messages . Carl Hanser Verlag, Munich 2000, p. 202. ISBN 3-446-19873-3
  10. ^ Gordon Welchman: The Hut Six Story - Breaking the Enigma Codes . Allen Lane, London 1982; Cleobury Mortimer M&M, Baldwin Shropshire 2000, pp. 113f. ISBN 0-947712-34-8
personal data
SURNAME Babbage, Dennis
ALTERNATIVE NAMES Babbage, Dennis William (full name)
BRIEF DESCRIPTION British mathematician and cryptanalyst
DATE OF BIRTH April 26, 1909
DATE OF DEATH June 9, 1991
Place of death Cambridge