PC Bruno

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Coordinates: 48 ° 44 '24 "  N , 2 ° 43' 19.2"  O PC Bruno was the code name of a secret intelligence means of Allied that successfully with the deciphering of the German Army using the rotor-key machine Enigma encrypted message traffic concerned. PC Bruno existed during the Second World War from October 1939 to June 1940. The abbreviation PC stood for the French expression poste de commandement (German: "Kommandoposten" or " Gefechtsstand "). Its seat was the Château de Vignolles (German: Schloss Vignolles) at Gretz-Armainvilliers , about 30 km southeast of Paris. It housed thePolish cryptanalysts of the Biuro Szyfrów (BS) (German: "Chiffrenbüro")who fledafter the Pyry meeting and the German attack on Poland that followed shortly afterwards. These included Marian Rejewski , Jerzy Różycki and Henryk Zygalski , their bosses Gwido Langer and Maksymilian Ciężki , as well as other employees of the BS and the AVA plant , such as Antoni Palluth and Edward Fokczyński . With the German offensive against France in June 1940 they had to flee again from the advancing Wehrmacht and found a new location (camouflage name: "Cadix" ) near Uzès in the free southern zone of France .

prehistory

→ Main article: History of the Enigma

The Polish cryptanalyst Marian Rejewski (1932)

After the invention of the Enigma in 1918 by the German Arthur Scherbius , this innovative type of machine encryption was used by the Reichswehr of the Weimar Republic from the mid-1920s, initially on a trial basis and increasingly regularly from 1930 . Germany's neighbors, above all France, Great Britain and Poland, followed this with suspicion, especially when the National Socialist rule began in 1933 and this key machine established itself as a standard procedure in the course of the armament of the Wehrmacht . While it failed French and the British, in the encryption break and they classified the Enigma as "unbreakable," the 27-year-old Polish mathematicians succeeded Marian Rejewski in his work in the charge of Germany Unit BS4 of the Polish Biuro Szyfrów (BS) (German : "Chiffrenbüro"), the first break-in in 1932 (see also: Deciphering the Enigma ). To do this, he and his colleagues Jerzy Różycki and Henryk Zygalski exploited a serious procedural error that the Germans had made.

The BS's cryptanalytic successes could, despite the repeated cryptographic complications introduced by the German side, be continued continuously until 1939, while at the same time French and British authorities tried in vain to decipher the Enigma. In addition to Enigma replicas, the Polish specialists also constructed two machines specifically for deciphering, called cyclometers and bombs , which embodied two or three Enigma machines connected in series and each shifted by three rotary positions. Shortly before the German attack on their country and in view of the acute threat, they decided to pass on all their knowledge about the identified weaknesses of the machine and the German procedures as well as their tried and tested methods for their deciphering and deciphering results to their allies. On July 26 and 27, 1939, the legendary secret meeting of French, British and Polish code breakers took place in the Kabaty Forest of Pyry, about 20 km south of Warsaw, at which the Poles exposed their successful methods to the astonished British and French.

Shortly afterwards, in September 1939, the BS specialists had to flee Poland because of the advancing Wehrmacht and found asylum in France. They were hospitably received by their French allies and, together with them, were able to resume and successfully continue their deciphering work against the German machine. For this purpose, the French, under the leadership of Commandant ( Major ) Gustave Bertrand , made the Château de Vignolles available to them, where they began their work in October 1939 under the code name PC Bruno .

structure

In addition to the 15 or so specialists who had fled from Poland (P), PC Bruno included around 50 French (F) employees and a British (B) liaison officer. Similar to Biuro Szyfrów before , it was divided into several sections (French: Sections ).

job

In the months to come, from October 1939, a fruitful collaboration developed not only between the French and Polish code breakers near Paris, but also with their allies on the other side of the English Channel , the British code breakers in Bletchley Park (BP), England . From December 3 to 7, 1939, Langer and Braquenié visited their colleagues from BP and intensified multilateral cooperation. It was agreed not to bring the Polish specialists to the United Kingdom , but to leave them in France, where the Polish government-in-exile had also established itself and the Polish armed forces were newly formed.

PC Bruno and BP worked intensively and successfully together on the further breakage of the German machine. Interestingly, they exchanged their information with each other over the radio, of course they encrypted the radio messages so that no one could read the secret information. To do this, they used an encryption method that they knew was extremely difficult to decipher - the German Enigma.

In January 1940 she visited Alan Turing , one of the leading code breakers from BP, and discussed important details of their deciphering procedures with them, especially with Rejewski. In the same month, on January 17th, the first breach of Enigma radio messages from the war time, on October 25th and 28th, 1939. In the following weeks they succeeded faster and faster, first those from the German Air Force and later also to break the messages encrypted by the army with the Enigma I. From April 4, they were able to read the encrypted German radio messages within 24 hours. The intelligence services and information relevant to the war effort derived from this were summarized by the British under the code name “ Ultra ”. Over the next few months they deciphered several thousand German radio messages and sometimes knew the plaintexts before the authorized German recipients had deciphered them. They became so important military information, for example about the ongoing in April 1940 German invasion of Norway (code name "Company Weser Exercise") and by 10 May of the same year Wehrmacht launched offensive in the West that the occupation of the Netherlands , Belgium and Luxembourg led ( "Fall Yellow" ).

With the further advance of the Wehrmacht in June 1940 ( "Fall Rot" ), the French capital and thus also the PC Bruno base, only a few kilometers away, came into acute danger. Shortly after midnight on June 10th, Bertrand therefore decided to evacuate and flew with his employees to Oran in Algeria . France capitulated shortly afterwards and was divided. While the northern and western parts came under German occupation, the southern part remained unoccupied and declared a zone libre (German: "Free Zone") . In September, Bertrand and his team secretly returned to France and continued their work at a new location in the Château de Fouzes (German: Schloss Fouzes) near the southern French community of Uzès in the zone libre . They chose “Cadix” as their new cover name .

literature

  • Friedrich L. Bauer : Deciphered Secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin et al. 2000, ISBN 3-540-67931-6 .
  • Gustave Bertrand : Énigma ou la plus grande enigme de la guerre 1939–1945 . Librairie Plon, Paris 1973.
  • Chris Christensen: Review of IEEE Milestone Award to the Polish Cipher Bureau for `` The First Breaking of Enigma Code '' . Cryptologia . Rose-Hulman Institute of Technology. Taylor & Francis, Philadelphia PA 39.2015,2, pp. 178-193. ISSN  0161-1194 .
  • Ralph Erskine : The Poles Reveal their Secrets - Alastair Dennistons's Account of the July 1939 Meeting at Pyry . Cryptologia. Rose-Hulman Institute of Technology. Taylor & Francis, Philadelphia PA 30.2006,4, pp. 294-395. ISSN  0161-1194 .
  • John Gallehawk: Third Person Singular (Warsaw, 1939) . Cryptologia. Rose-Hulman Institute of Technology. Taylor & Francis, Philadelphia PA 3.2006,3, pp. 193-198. ISSN  0161-1194 .
  • Francis Harry Hinsley , Alan Stripp: Codebreakers - The inside story of Bletchley Park . Oxford University Press, Reading, Berkshire 1993, ISBN 0-19-280132-5 .
  • David Kahn : The Code Breakers - The Story of Secret Writing . Macmillan USA, Reissue 1974, ISBN 0-02-560460-0 .
  • David Kahn: Seizing the Enigma - The Race to Break the German U-Boat Codes, 1939-1943 . Naval Institute Press, Annapolis, MD, USA, 2012, ISBN 978-1-59114-807-4 .
  • Władysław Kozaczuk : Enigma - How the German Machine Cipher Was Broken, and How It Was Read by the Allies in World War Two . Edited and translated by Christopher Kasparek, Frederick, MD, University Publications of America, 1984, ISBN 0-89093-547-5 .
  • Władysław Kozaczuk: Enigma - How the German Machine Cipher Was Broken, and How It Was Read by the Allies in World War Two . Edited and translated by Christopher Kasparek, Frederick, MD, University Publications of America, 1984, ISBN 0-89093-547-5 .
  • Władysław Kozaczuk, Jerzy Straszak, Enigma - How the Poles Broke the Nazi Code . Hippocrene Books, 2004, ISBN 0-7818-0941-X .
  • Władysław Kozaczuk: Secret Operation Wicher . Bernard et al. Graefe, Koblenz 1989, Karl Müller, Erlangen 1999, ISBN 3-7637-5868-2 , ISBN 3-86070-803-1 .
  • Władysław Kozaczuk: Under the spell of Enigma . Military publishing house, Berlin 1987, ISBN 3-327-00423-4 .
  • Hugh Sebag-Montefiore : Enigma - The battle for the code . Cassell Military Paperbacks, London 2004, ISBN 0-304-36662-5 .
  • Dermot Turing : X, Y & Z - The Real Story of how Enigma was Broken. The History Press , Stroud 2018, ISBN 978-0-75098782-0 .
  • Gordon Welchman : The Hut Six Story - Breaking the Enigma Codes . Allen Lane, London 1982; Cleobury Mortimer M&M, Baldwin Shropshire 2000, ISBN 0-947712-34-8 .

Web links

Individual evidence

  1. ↑ Simon Singh: Secret Messages . Carl Hanser Verlag, Munich 2000, p. 199. ISBN 3-446-19873-3 .
  2. ^ Marian Rejewski: An Application of the Theory of Permutations in Breaking the Enigma Cipher . Applicationes Mathematicae, 16 (4), 1980, pp. 543-559. Accessed: April 15, 2015. PDF; 1.6 MB ( Memento of the original from October 30, 2014 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / cryptocellar.web.cern.ch
  3. ↑ a b Ralph Erskine: The Poles Reveal their Secrets - Alastair Dennistons's Account of the July 1939 Meeting at Pyry . Cryptologia. Rose-Hulman Institute of Technology. Taylor & Francis, Philadelphia PA 30.2006,4, p. 294.
  4. ↑ Poste de Commandement Bruno Accessed: May 6, 2015 (English).
  5. ↑ David Kahn: Seizing the Enigma - The Race to Break the German U-Boat codes 1939 -1943 . Naval Institute Press, Annapolis, MD, USA, 2012, p. 92. ISBN 978-1-59114-807-4 .
  6. ^ 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 .
  7. ↑ a b Gordon Welchman: The Hut Six Story - Breaking the Enigma Codes . Allen Lane, London 1982; Cleobury Mortimer M&M, Baldwin Shropshire 2000, p. 220. ISBN 0-947712-34-8 .
  8. ^ Hugh Sebag-Montefiore: Enigma - The battle for the code . Cassell Military Paperbacks, London 2004, p. 22. ISBN 0-304-36662-5 .