Key device 41

from Wikipedia, the free encyclopedia
Key device 41 in the fortress museum Reuenthal . The keyboard with the 26 capital letters of the Latin alphabet is easy to recognize .

The key device 41 (SG-41) was a mechanical key machine . Towards the end of the Second World War , it was used in relatively small numbers by the German Abwehr (secret service).

history

An SG-41 ready for " keying "

The cipher device 41 was developed on behalf of the Heereswaffenamt ( OKH / Wa Prüf 7 / IV) with the collaboration of the German cryptologist Fritz Menzer (1908-2005) and built by the Wanderer company , a leading manufacturer of typewriters at the time , in Chemnitz . The SG-41, the name of which indicates that construction began in 1941, was also known as the “Hitler Mill” because of the crank attached to the side  (picture) . Unlike the standard Enigma key machine used by the Wehrmacht in numbers of tens of thousands at that time  , it had no letter lamps, but worked with two strips of paper, one printed out the entered letter sequence, the other the result of the encryption or decryption process . Due to the war-related lack of light metals such as aluminum and magnesium , the device weighed around 13.5 kg more than originally designed, and was therefore actually too heavy for field use.

According to the motto "... now the ENIGMA must die", the SG-41 was originally intended to replace the Enigma, which was no longer considered safe, across the board. The Luftwaffe and Army ordered around 11,000 copies.

Occasionally it is assumed that only around 500 of the device were manufactured due to bottlenecks caused by the war. In fact, however, the head of the Wehrmacht News Connections Office Group (AgWNV) in the OKW , Major General Thiele , recognized the weight of the SG-41 as too high for use at the front and already on December 18, 1943, during a meeting in the OKW / WNV office, determined that only 1000 units were to be produced by the end of 1944. From October 12, 1944, extradition to the Abwehr began. In the last months of the war, the latter began to use the encryption device instead of the previously used Enigma-G .

function

The six key wheels can be seen through the control flap
The conspicuous red key (J) was used (according to the number assignment shown above) for the makeshift display of numbers in alphabetical plain text, such as "41" through "JRQJ"

In its operation, the key device resembled not the Enigma, but the C-machinery company Hagelin . It had six key wheels, while the Enigma I only had three and the Enigma-M4 used by the German submarines had four. According to research, the SG-41 had advanced features that increased its cryptographic security compared to the Enigma models and contemporary Hagelin machines. Specifically, the mechanical progression of the key wheels was extremely irregular and the key wheels influenced each other's movements. Comparable features did not appear until 1952 with the commercially available Hagelin CX-52 machine .

Cryptanalysis

For the British code breakers in Bletchley Park , England , the code device 41 remained a “ mystery ”. A message encrypted with the SG-41 was only broken in rare individual cases, namely when there was a depth ( clear-text-clear-text compromise ) . The exact functionality of the German device could not be reconstructed. In this respect, Bletchley Park did not succeed in carrying out a systematic cryptanalysis or even developing a promising deciphering method against the encryption device . The Allies respectfully called it a remarkable machine ( German "remarkable machine" ).  

SG-41Z

A further 550 copies were made during the last months of the war up to April 1945. It was probably the SG-41Z version . This model had only ten number keys (instead of the 26 letter keys of the SG-41) and was used to encrypt weather reports. It is believed that the Air Force used it on their weather intelligence network.

Find of Aying

On May 5, 2017, the two hobby treasure hunters Max Schöps and Volker Schranner found an SG-41 in a forest near the Upper Bavarian town of Aying , which had been buried about half a meter in the ground, probably since the end of the war in 1945. The two finders refrained from selling it privately, which would certainly have been possible with a high financial profit, but handed it over to the Deutsches Museum and thus to the public. It is intended to preserve the key device in its current condition and to display it in the new permanent exhibition Image - Script - Codes from the end of 2019 . This extends the previous cryptological cabinet of the museum, which was originally built there from 1984 by the Munich university professor Friedrich L. Bauer (1924–2015) and opened in 1988.

The find also led to a legal battle. After the device was handed over to the Deutsches Museum, the responsible monument authority felt ignored and complained of alleged violations of the Monument Protection Act . Max Schöps then sued Bavaria's State Office for Monument Preservation in order to clarify the fundamental question of what probe users or hobby treasure hunters are allowed to do : where does the hobby or adventure end and professional archeology and monument protection begin ? The Munich Administrative Court basically regards archaeologists as responsible for the legacies of World War II . In the case of finds by hobby treasure hunters, however, it differentiated that objects from the years after 1945 and so-called mass finds (such as cartridge cases or Reichspfennige ) are not always monuments . The proceedings were discontinued after an agreement between Schöps and the monument office. However, the topic is so complicated that, according to the German Probe Union (DSU), lawsuits on the topic are still pending in at least six federal states at the beginning of 2019.

literature

  • Mavis Batey : Dilly - The Man Who Broke Enigmas , Dialogue, 2011, ISBN 978-1906447151
  • NSA : European Axis Signal Intelligence in World War II - Volume 2: Notes on German High Level Cryptography and Cryptanalysis PDF; 7.1 MB (English)
  • NSA: German Cipher Machines of World War II , PDF; 1.1 MB (English)
  • Michael Pröse: Encryption machines and deciphering devices in World War II - the history of technology and aspects of IT history , dissertation at Chemnitz University of Technology, Leipzig 2004. PDF; 7.9 MB
  • Klaus Schmeh : Code breakers versus code makers. The fascinating story of encryption. 2nd Edition. W3L-Verlag, Herdecke u. a. 2008, ISBN 978-3-937137-89-6 .

Web links

Individual evidence

  1. ↑ a b c NSA: German Cipher Machines of World War II , p. 25.
  2. ↑ a b c d e Michael Pröse: Encryption machines and deciphering devices in the Second World War - the history of technology and aspects of the history of computer science , dissertation at Chemnitz University of Technology, Leipzig 2004, p. 64.
  3. ↑ a b c Mavis Batey: Dilly - The Man Who Broke Enigmas , Dialogue, 2011, p. 212, ISBN 978-1906447151
  4. ↑ Michael Pröse: Encryption machines and deciphering devices in World War II - the history of technology and aspects of IT history , dissertation at Chemnitz University of Technology, Leipzig 2004, p. 65.
  5. ^ Klaus Schmeh: Codeknacker gegen Codemacher , W3L-Verlag, Dortmund 2014, p. 373.
  6. ↑ a b Key device 41 in the Crypto Museum (English), accessed on September 14, 2017
  7. ↑ European Axis Signal Intelligence in World War II - Volume 2: Notes on German High Level Cryptography and Cryptanalysis (English) ( Memento from June 11, 2014 in the Internet Archive ) (PDF; 7.5 MB), p. 29
  8. ↑ The Hagelin C-52 and CX-52 Cipher Machines (English)
  9. ↑ The SG41-Z cipher device from Fritz Menzer (1908-2005)
  10. ↑ Numerical version in the Crypto Museum (English)
  11. ↑ Treasure hunters find the "Hitlermühle" cipher device ( Memento from December 29, 2017 in the Internet Archive ) BR from August 18, 2017
  12. ↑ Treasure hunters find a rare copy of the "Hitlermühle" Süddeutsche Zeitung, accessed on September 11, 2017
  13. ↑ Friedrich L. Bauer: Deciphered secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin et al. 2000, p. VIII.
  14. ↑ Britta Schultejans and Uwe Stiehler: Trouble with the "Hitlermühle" . In Märkische Oderzeitung on February 4, 2019, p. 17