Enigma-Z

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The Enigma-Z (more precisely: Enigma-Z30 , also written Enigma Z or ENIGMA Z and also called Enigma Model Z ) is a rotor key machine especially for encrypting numbers, which was manufactured in the early 1930s and sold in small numbers .

history

The Enigma-Z was developed around 1930 by Chiffriermaschinen-Aktiengesellschaft in Berlin ( W 35 , Steglitzerstr. 2, today Pohlstrasse, 10785 Berlin- Mitte / Tiergarten) and was offered for sale in the early 1930s for 600  RM . It was only produced in small numbers. In November 1931 it was offered to the Spanish Foreign Ministry on request. However, the Spaniards did not decide to buy it. Enigma Z models were sold to Chile and Sweden, where three well-preserved copies (with the serial numbers Z101, Z102 and Z103) were found in 2015. These are now in the cryptological collection of the museum of the FRA ( Försvarets radioanstalt ; German: "Radio facility for national defense"), an organization of the Swedish Ministry of Defense.

In September 1943, in the middle of the Second World War , an Enigma-Z (with the serial number Z106) was delivered to the encryption department of the Wehrmacht High Command (OKW / Chi). It was received there by Erich Hüttenhain , one of the leading cryptanalysts in the Wehrmacht . The Norwegian historian and cryptologist Frode Weierud suspects that the OKW / Chi, which was working on machine procedures to encrypt the weather reports, which mainly consisted of columns of numbers, acquired the Enigma-Z for study purposes. In fact, from August 1944 a variant of the cipher device 41 was introduced, called SG41Z.

construction

The Enigma-Z (without wooden housing) weighs a good 4 kg with the battery and its dimensions (L × W × H) are around 160 mm × 220 mm × 110 mm. Unlike all other Enigma models that the encryption of texts were designed, plus the 26 capital letters of the Latin alphabet used, the Enigma-Z was used for encryption and decryption of numbers , for example for superencryption diplomatic codes. Instead of individual letters, it encrypts numbers . The Enigma-Z has a keyboard with ten keys that are arranged like the top line of a modern keyboard. These show the ten digits (and no letters or special characters) in the following order:

1   2   3   4   5   6   7   8   9   0

Similar to the structure of the Enigma I later used by the military, the lamp field is located above the keyboard and the set of rollers above it. In the case of the Enigma-Z, the display, like the keyboard, consists of only one line. Ten circular viewing windows showing the numbers 1 to 0 are arranged next to one another. One of them lights up as soon as a key is pressed. For this purpose, there is a small light bulb behind each viewing window , which is made to glow with the help of an internal battery. Alternatively, the machine can also be operated with mains electricity. In the machine's housing, between the keyboard and the row of lamps, there is a metal rail with eight places for replacement lamps. These are - like the ten number lamps arranged immediately above - easily accessible when the lid is open. A burnt-out lamp can be replaced quickly and easily.

Compared to all other Enigma models , the rotors of the roller set have a significantly smaller diameter and only ten contacts on each side. As with many other models, there are three through rollers that can be inserted into the machine in a freely selectable order. This gives 3 x 2 x 1 or six possible permutations . There is also a reversing roller (VHF) on the far left of the roller set , which cannot be replaced and which only has contacts on its right side. In contrast to most other Enigma models, the rotation position of the VHF can be freely adjusted and it rotates with the encryption. The Enigma-Z is a real four-roller machine with four rotating rollers. (Only a few other models, such as the Enigma-G , have this property . Even the much more modern Enigma-M4 can only rotate three rollers.) The wiring of the rollers (I to III and the VHF) of the Enigma-Z could be based on of the specimens found in 2015.

        1 2 3 4 5 6 7 8 9 0
I       6 4 1 8 2 7 0 3 5 9
II      5 8 4 1 0 9 7 6 3 2
III     3 5 8 1 6 2 0 7 9 4
UKW     5 0 7 9 1 8 3 6 4 2

Apart from the ten characters only has the Enigma-Z many similarities in structure and function to other models, such as the Enigma D and Enigma I . The reels are switched on as with a mechanical odometer , but with a freely selectable transfer point. For this purpose, all rollers have rotatable and freely adjustable rings , each with exactly one notch. This can be used to set the point of roll transfer. The anomaly of the roll advance known from the Enigma I is also present. This means that the period is not 10 4 or 10,000, as one would expect with four rotors with ten positions each, but is reduced by 10 3  + 9 · 10 2 or 1900. The period of the Enigma-Z is 8100 characters. In contrast to the Enigma I, like all early Enigma models, the machine does not have a plug board . The Enigma-Z, like other Enigma models, has significant cryptographic weaknesses . This includes involutorism and freedom from fixed points .

literature

Web links

  • Photo accessed on February 21, 2019.
  • Enigma Z in the Crypto Museum (English) Photo and description of the Enigma-Z; accessed on December 21, 2015.
  • Enigma Z on Jerry Proc's website (English) Photo and description of the Enigma-Z; accessed on December 21, 2015.
  • Patent specification No. 607 638 (patented in the German Empire on March 5, 1930), accessed on February 22, 2019.

Individual evidence

  1. a b Arturo Quirantes: Model Z - A Numbers-Only Enigma Version. In: Cryptologia , Vol. 28/2, January 2002, p. 153. doi: 10.1080 / 0161-110491892845 .
  2. Anders Wik: Enigma Z30 retrieved. In: Cryptologia , 2015, p. 3. doi: 10.1080 / 01611194.2015.1055387 .
  3. Anders Wik: Enigma Z30 retrieved. In: Cryptologia , 2015, p. 5. doi: 10.1080 / 01611194.2015.1055387 .
  4. Arturo Quirantes: Model Z - A Numbers-Only Enigma Version. In: Cryptologia , Vol. 28/2, January 2002, p. 154. doi: 10.1080 / 0161-110491892845 .
  5. a b Anders Wik: Enigma Z30 retrieved. In: Cryptologia , 2015, p. 4. doi: 10.1080 / 01611194.2015.1055387 .