Willi Korn

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Willi Korn (* 1893, † after 1945) was a German engineer (Dipl.-Ing.) And cryptologist who in the first half of the 20th century significantly to the design of the rotor cipher machine Enigma has helped that during the Second World War to Encryption of the message traffic of the German armed forces served.

Life

The “trading machine” (1923) invented by Willi Korn's later boss, Arthur Scherbius, did not have a reverse roller
The Enigma's reversing roller is probably Korn's most famous invention
The set of rollers of the later Enigma I contained the rings invented by Willi Korn as an important cryptographic complication. The ring of the middle roller is set to 01 here (see red triangle in the middle of the picture). To do this, the clip was pulled out sideways to the right and the ring, which was now freely movable on the roller body, was rotated until the red triangle pointed to the "ring position 01" prescribed here. When you let go of the clip, a small bolt engages in the hole at 01 (an “empty” one can be clearly seen above to the right of 02). This will lock the ring in place.
Key device 41 in the fortress museum Reuenthal . The keyboard with the 26 capital letters of the Latin alphabet is easy to recognize .

Little is known about Korn's life. He was 15 years younger than Arthur Scherbius (1878–1929), the inventor of the Enigma. To manufacture this machine, the Chiffriermaschinen-Aktiengesellschaft (ChiMaAG) was founded in Berlin on July 9, 1923 ( W 35 , Steglitzerstr. 2, today Pohlstrasse , 10785 Berlin- Mitte / Tiergarten ). According to Friedrich L. Bauer , Willi Korn came to ChiMaAG in 1929.

More than three years earlier he had invented the reverse roller (VHF) for the Enigma. At this time only the early Enigma models existed , such as the " trading machine " and the " writing Enigma " (see also: Enigma family tree under web links ), which had no reverse roller and were suitable for practical use due to their size and high weight were not considered optimal. With his idea for VHF, Korn intended to improve the Enigma in such a way that both the operation and construction of the machine were simplified and the cryptographic security increased. The German Reich patent with the number 460457 and the title “Cipher device for use in cipher machines” bears the note “Patented in the German Empire from March 11, 1926” and the inventor is “Willi Korn in Berlin-Friedenau ”. Ten days later, "Patented in the German Empire from March 21, 1926", another patent from Korn is valid. It bears the number 452194 and the title "Electrical device for encryption and decryption".

In the first document, the replacement of individual rollers and the VHF as such are patented. The possibility invented by Korn to swap individual rollers in the roller set and also to provide additional rollers that are used instead of those in the roller set undoubtedly represents a considerable increase in the combinatorial complexity of the machine and thus an improvement in the cryptographic security of the Enigma .

The second patent describes further refinements of the VHF, such as setting, replacing and rotating the VHF during encryption . Since the patents were granted in March 1926, it can be assumed that Korn had the idea for VHF much earlier, probably as early as 1924 or even earlier. The Enigma C , the first "incandescent lamp Enigma", was also the first machine to have a VHF. Almost all of the following Enigma models, especially those used many years later in the war up to the Enigma-M4 , had a VHF. In the second patent, Korn explains the advantages of his invention with the words: “This reduction in the current through the cipher roller set causes further scrambling. As a result of this arrangement, it is possible to get by with relatively few encryption rollers and still maintain a high level of encryption security. ”This is apparently correct, because the current now flows through the rollers twice. Indeed, through the VHF, he succeeded in making the key procedure involutor . This means that if a U is encoded into an X at a certain position of the Enigma rollers , then an X is encoded into a U at this position. In this way, he simplified the operation and construction of the machine, because you no longer need to differentiate between encryption and decryption. The hoped-for increase in cryptographic security, however, turned out to be a fallacy with far-reaching consequences (see also: Cryptographic weaknesses of the Enigma ).

In 1928 he invented the "lock ring" (the later ring positions ), an effective cryptographic improvement of the machine. This invention clearly came from him and not, as has been wrongly published several times, from his colleague Paul Bernstein . In the years up to 1930 further patents from Korn were granted, which had other, mostly practical improvements of encryption machines on the topic (see also: Enigma patents ). According to an American post-war report on the encryption department of the Wehrmacht High Command (OKW / Chi), Korn later worked with the head of the main group cryptanalysis there , Ministerialrat Wilhelm Fenner , on the further development of the Enigma.

During the Second World War, Korn, then chief engineer at Heimsoeth & Rinke , the successor to ChiMaAG since 1934, also worked on other, innovative key machines, such as the key device 41 (SG-41). According to a 1946 report by the American Army Security Agency, this machine would probably have been practically unbreakable . However, due to technical and supply problems, it was no longer used in the field.

Willi Korn survived the Second World War. His further fate is unknown.

literature

  • Army Security Agency (ASA) : Notes on German High Level Cryptography and Cryptanalysis . European Axis Signal Intelligence in World War II, Vol 2, Washington (DC), 1946 (May). Accessed: September 16, 2018. PDF; 63 MB
  • 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 .
  • 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 .

Web links

  • Enigma Family Tree Family tree of the Enigma (English). Retrieved: February 29, 2016.
  • Enigma Patents Enigma Patents in the CryptoMuseum (English). Retrieved: February 29, 2016.

Individual evidence

  1. ↑ Louis Kruh, Cipher Deavours: The commercial Enigma - Beginnings of machine cryptography . Cryptologia, Rose-Hulman Institute of Technology, Taylor & Francis, Philadelphia PA 26.2002,1 (January), p. 2. ISSN  0161-1194 Retrieved February 29, 2016. PDF; 0.8 MB
  2. ^ Friedrich L. Bauer: Historical Notes on Computer Science . Springer, Berlin 2009, p. 207. ISBN 3-540-85789-3 .
  3. ↑ Patent specification Electrical device for encryption and decryption DRP No. 452 194, p. 1. Accessed: February 29, 2016. PDF; 0.5 MB
  4. ↑ David Kahn: Seizing the Enigma - The Race to Break the German U-Boat codes 1939 -1943 . Naval Institute Press, Annapolis, MD, USA, 2012, p. 42. ISBN 978-1-59114-807-4 .
  5. ↑ Friedrich L. Bauer: Deciphered secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin et al. 2000, p. 417.
  6. ↑ US1905593 Coding Machine. 5 claims Application date November 12, 1929 and in Germany November 16, 1928 (PDF; 487 kB). Granted April 25, 1933. Applicant: Willi Korn of Berlin-Friedenau, Germany, accessed June 5, 2019.
  7. ↑ Friedrich L. Bauer: Deciphered secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin a. a. 2000, p. 117.
  8. ^ Colleen Carper: Bletchley's Secret War - British Code Breaking in the Batlle of the Atlantic. Ashbrook Statesmanship Thesis, 2009, p. 3, PDF
  9. ↑ Louis Kruh, Cipher Deavours: The Commercial Enigma - Beginnings of Machine Cryptography . Cryptologia, Vol.XXVI, No. 1, January 2002, p. 11. apprendre-en-ligne.net (PDF; 0.8 MB), accessed on February 18, 2019.
  10. ^ Army Security Agency: The Signal Intelligence Agency of the Supreme Command, Armed Forces . European Axis Signal Intelligence in World War II, Vol 3, Washington (DC), 1946 (May), p. 119. Retrieved September 16, 2018. PDF; 44.9 MB
  11. ^ Army Security Agency: Notes on German High Level Cryptography and Cryptanalysis . European Axis Signal Intelligence in World War II, Vol 2, Washington (DC), 1946 (May), p. 17, accessed September 16, 2018. PDF; 63 MB
personal data
SURNAME Korn, Willi
BRIEF DESCRIPTION German cryptologist
DATE OF BIRTH 1893
DATE OF DEATH after 1945