B-21 (machine)

from Wikipedia, the free encyclopedia
B-21 cipher machine (left) by Boris Hagelin. An external characteristic of the B-21 is the keyboard with only 25 letters (W is missing) in contrast to the usual 26 letters of the Latin alphabet, such as the Enigma on the right.

B-21 is the name of an electromechanical rotor cipher machine that was developed in 1925 by the Swede Boris Hagelin (1892-1983) at the Swedish company AB Cryptograph .

history

The prototype from 1925
View inside with the lid open
The characteristic 5 × 5 matrices stand out in the circuit diagram

The company AB Cryptograph ( AB is an abbreviation for Swedish Aktiebolaget , German  stock corporation , and Cryptograph refers to the field of "secret typewriters") was founded in Stockholm in 1915 by Hagelin's compatriot Arvid Damm (1869-1927) . Boris Hagelin joined the company in 1922 and developed his first encryption machine there in 1925 with the prototype of the B-21. The reason was that shortly before the Swedish General Staff had received a German Enigma machine for testing purposes. Hagelin heard about it and did not hesitate long. He visited the officer responsible and "explained to him that AB Cryptograph already had 10 years of experience in the field of encryption machines and that I could offer something that would be superior to" ENIGMA "." He was now given six months to prove his (somewhat brash) claim.

Within the set deadline, he succeeded in producing a sample device based on the Damm rotor cipher machine from 1919, in particular its “simplified through- wheel ”. His machine had a keyboard with 25 letters, two through wheels (similar to the Enigma rollers ), but - unlike the Enigma - their switching was controlled by two further key wheels with different pitches (17, 19, 21, 23), and a lamp field for display. Like the keyboard, the lamp field only had 25 letters. Hagelin dispensed with the usual 26 capital letters of the Latin alphabet on the rarely used letter W in Swedish . This could be replaced by VV if necessary. He also dispensed with umlauts ( Ä and Ö ) and the letter Å . The reason for this reduction to only 25 letters was that he could use a switching matrix of 5 × 5 rows and columns as the central element (see also: Circuit of the B-21 under web links ).

B-211

Around 1932 Hagelin developed a successor to the B-21 equipped with a printing mechanism instead of the lamp display and named it B-211 .

literature

Web links

Commons : B-21  - collection of pictures, videos and audio files

Individual evidence

  1. Boris Hagelin: The history of the Hagelin cryptos. Zug 1979, p. 16
  2. Boris Hagelin: The history of the Hagelin cryptos. Zug 1979, pp. 16-19