Enigma-C

The Enigma-C (also: Enigma C or Enigma Model C ) is an early model of the Enigma rotor key machine .

history

In the long history of the different Enigma models , the Enigma-C introduced in 1925 was chronologically the fifth model (see also: family tree of the Enigma under web links ) and the third of the so-called "incandescent lamp cipher machines".

To operate the light bulbs, the Enigma-C contained a built-in 4.5 volt battery . As the cryptographic heart, it had three rotating rollers (also called rotors) plus a fixed (non-rotating) reversing roller (VHF). The VHF could be used in the Enigma in two different positions.

What is striking about the Enigma-C is the simple alphabetical arrangement of the 26 keys and lamps in the following way:

 A   B   C   D   E   F   G   H   I
   J   K   L   M   N   O   P   Q
 R   S   T   U   V   W   X   Y   Z

Special variants

In addition to the basic model of the Enigma-C, there were, presumably at the customer's request, special equipment variants of the machine. One of them is the “radio key C” used by the Reichsmarine with 28 roller contacts, but 29 buttons and lamps each, whereby the umlauts Ä and Ü (but no Ö) were added to the 26 capital letters of the Latin alphabet . Curiously, the letter X was not encrypted here, but instead passed directly to the lamp X from the corresponding key.

A “Swedish Enigma” with 28 keys, roller contacts and lamps, similar to the remote control key C, showed the letters Ä and Ö, which are also used in Swedish , as well as the letters Å . There were no Ü and W. The latter was replaced by VV if necessary. This model cost 650 ℛℳ , weighed around 5 kg (excluding the wooden case) and its dimensions (L × W × H) were around 275 mm × 260 mm × 110 mm. Interestingly, such a variant of the Enigma-C delivered to a Swedish government agency in 1925 with the serial number A133 has been preserved. Today it is owned by the Swedish intelligence service FRA (see also: Photo of an Enigma-C for Sweden under web links ). It shows the following letter arrangement for keyboard and lamp field:

 A   B   C   D   E   F   G   H   I   J
  K   L   M   N   O   P   Q   R   S
   T   U   V   X   Y   Z   Å   Ä   Ö

literature

Friedrich L. Bauer : Deciphered Secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin a. a. 2000, ISBN 3-540-67931-6 .
Friedrich L. Bauer: Historical Notes on Computer Science . Springer, Berlin 2009, ISBN 3-540-85789-3 .
Louis Kruh, Cipher Deavours: The Commercial Enigma - Beginnings of Machine Cryptography . In: Cryptologia , Vol. 26 (1), January 2002, p. 1. apprendre-en-ligne.ne (PDF; 0.8 MB) accessed March 3, 2016.
Heinz Ulbricht: The Enigma cipher machine - deceptive security. A contribution to the history of the intelligence services . Dissertation. Braunschweig 2005. tu-bs.de (PDF; 4.7 MB)
Anders Wik: The First Classical Enigmas - Swedish Views on Enigma Development 1924–1930. Proceedings of the 1st International Conference on Historical Cryptology, PDF; 12.5 MB 2018, pp. 83-88.

Web links

Enigma-C in the Crypto Museum (English) accessed March 3, 2016.
Enigma Family Tree . Enigma family tree accessed March 3, 2016.
Photo of an Enigma-C for Sweden retrieved March 3, 2016.

Individual evidence

↑ Louis Kruh, Cipher Deavours: The commercial Enigma - Beginnings of machine cryptography . In: Cryptologia , Rose-Hulman Institute of Technology, Taylor & Francis, Philadelphia PA 26.2002,1 (January), p. 9. ISSN 0161-1194 Retrieved: March 3, 2016. apprendre-en-ligne.net (PDF; 0 , 8 MB), accessed March 3, 2016.
↑ Heinz Ulbricht: The Enigma encryption machine - Deceptive security . A contribution to the history of the intelligence services. Dissertation Braunschweig 2005, p. 4. tu-bs.de (PDF; 4.7 MB)
^ Francis Harry Hinsley, Alan Stripp: Codebreakers - The inside story of Bletchley Park . Oxford University Press, Reading / Berkshire 1993, plate 3. ISBN 0-19-280132-5 .
↑ Anders Wik: The First Classical Enigmas - Swedish Views on Enigma Development 1924–1930. Proceedings of the 1st International Conference on Historical Cryptology, PDF; 12.5 MB 2018, p. 86.
^ ^A ^b Anders Wik: The First Classical Enigmas - Swedish Views on Enigma Development 1924–1930. Proceedings of the 1st International Conference on Historical Cryptology, PDF; 12.5 MB 2018, p. 85.

[1] Louis Kruh, Cipher Deavours: The commercial Enigma - Beginnings of machine cryptography . In: Cryptologia , Rose-Hulman Institute of Technology, Taylor & Francis, Philadelphia PA 26.2002,1 (January), p. 9. ISSN 0161-1194 Retrieved: March 3, 2016. apprendre-en-ligne.net (PDF; 0 , 8 MB), accessed March 3, 2016.

[2] Heinz Ulbricht: The Enigma encryption machine - Deceptive security . A contribution to the history of the intelligence services. Dissertation Braunschweig 2005, p. 4. tu-bs.de (PDF; 4.7 MB)

[3] Francis Harry Hinsley, Alan Stripp: Codebreakers - The inside story of Bletchley Park . Oxford University Press, Reading / Berkshire 1993, plate 3. ISBN 0-19-280132-5 .

[4] Anders Wik: The First Classical Enigmas - Swedish Views on Enigma Development 1924–1930. Proceedings of the 1st International Conference on Historical Cryptology, PDF; 12.5 MB 2018, p. 86.

[Wik-S85-5] A ^b Anders Wik: The First Classical Enigmas - Swedish Views on Enigma Development 1924–1930. Proceedings of the 1st International Conference on Historical Cryptology, PDF; 12.5 MB 2018, p. 85.