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Transvertex was a Swedish manufacturer of ciphering machines (crypto). The company started life in the early 1950s and was taken over by LM Ericsson in 1969. Over the years they manufactured a range of encryption devices, mainly for use by the Swedish Army, but also for other countries.

Transvertex logo, copyright Crypto Museum

The company was established by Per-Erik Ahlman, W. Jonsson and Vigo Lindstein at a meeting on 12 July 1950. The initial goal was to manufacture the so-called HC cipher machine, developed by Vigo Lindstein in the late 1940s. As Lindstein was a former employee of Boris Hagelin he had to avoid patent infringement. The HC-machine would later evolve into the well-known HC-9 [1].

Not much happened after the initial meeting, and it wasn't until 15 January 1951, when the founders met again, that the company was officially established with Lindstein as CEO. The initial name of the company was Invertex, hence the logo of the interwoven letters I and X. The first machine to be manufactured by Invertex was the SA-1 Teletype Ciphering Machine [1].

As the name Invertex was already registred by another company, the name was changed to AB Transvertex, but the original logo was kept. Transvertex arrived at the scene at a time when Boris Hagelin was moving his company AB Cryptoteknik (later: Hagelin, later: Crypto AG) from Sweden to Switzerland in order to circumvent new Swedish export laws.

Transvertex cipher machines on this website
Early history
During WWII, Transvertex co-founder Vigo Waldemar Lindstein worked for LM Ericsson Kassa Register (Cash Registers). As he was a gifted engineer, he was given the task to devise a machine for the automatic decryption of the Siemens T-52 A/B Geheimschreiber, that was used by the German Army [3]. The T-52 had been broken by the Swedish cryptanalist Arne Beurling in May 1940, and Beurling wanted Lindstein to build a machine that simulated the Geheimschreiber. In August 1940 the machine (called 'app') was ready and by the end of 1940, after a series of improvements, 33 such machines were in operation.

After his work on the Geheimschreiber, Lindstein became Chief Engineer at the Hagelin company (AB Cryptoteknik), which is where he gained his knowledge of pin-wheel based cipher machines. Back in 1935, Hagelin's C-35 had been the first fully mechanical pin-wheel machine. Hagelin's company was well-known to Ericsson, as they supplied their first cipher machine, the B-21, to Ericsson for sending secure messages over insecure telephone lines in South-America [4]. Some of these machines were even built by Ericsson under license of Hagelin.

In the early 1950s, the Swedish government passed a law that put restrictions on the export of cipher machines and Boris Hagelin made plans to move his company to Switzerland. Linstein left the company and teamed up with Per-Erik Ahlman and W. Johnsson to form a new company that would become known as Transvertex.

Over the years, Transvertex manufactured a range of mechanical and electronic cipher machines, mainly for the Swedish Army. Some of their machines found their way into other countries, such as Brasil and Argentina. In the early years, most of the design work was done by Vigo Waldemar Lindstein and Per Erik Ahlman. in the early 1960s, their work was taken over by Bengt Florin of Hagersten (Finland) and Kalevi Loimaranta of Mattby (Finland) [2]. In December 1969, Transvertex was bought by the Swedish telephone equipment manufacturer Telefonaktiebolaget L.M. Ericsson, currently known as Ericsson. Lindstein was CEO until the takeover by Ericsson [1].

In the early 1950s, Transvertex developed the HC-9 cipher machine for the Swedish Army. It's a fully mechanical machine that physically resembles Hagelin cipher machines, such as the M-209, but uses a punched card instead of pin-wheels.

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Over the years, a number of patents have been filed on behalf of Transvertext, in a variety of countries. In the beginning most designs were made by Vigo Lindstein and Per-Erik Ahlman. In later years patents were often attributed to Florin Bengt and Loimaranta Kalevi (both from Finland).

We've listed the patents that we have found on a separate page. You can help us by finding more patents.

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  • SA-1
    Teletype Ciphering Machine
  • HC-9
    Portable mechanical cipher machine
  • HC-110
    Compact offline electronic ciphering device
  • TC-213
    Online/offline cipher machine for teleprinters (telex)
  • SV-250
    Speech encryption device
  • ST-320
    Military voice encryption device for radio
  • CD-410
    Multiplexed digital data encryptor with PCM and CVSD
  • TD-265
    Full-duplex line encryptor with HDLC
  1. Torbjörn Andersson, Transvertex, Swedish Manufacturer of Ciphering Machines
    Information about Transvertex reproduced here with permission from the author.

  2. US Patent 3557307, Ciphering Machine
    19 January 1971. This patent gives details about Florin and Loimaranta.

  3. CG McKay and Bengt Beckman, Swedish signal intelligence 1900-1945
    2003. ISBN 9780714652115 (hard cover). ISBN 0-7146-5221-3 (cloth cover).

  4. Crypto Museum, Hagelin B-21 cipher machine
    Example of a B-21 that was actually used by LM Ericsson.
Further information
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Crypto Museum. Created: Tuesday 04 August 2009. Last changed: Saturday, 24 February 2018 - 21:31 CET.
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