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STK   Alcatel Thales
Standard Telefon og Kabelfabrik

STK, or Standard Telefon og Kabelfabrik, was a telephone, electronics and cable company in Oslo (Norway). They are commonly referred to as Standard. STK was establised in 1915 and was later owned by ITT, then Alcatel and finally Thales.
STK-logo. Copyright Crypto Museum

The company was establised in 1915 as the Scandinavian Cable and Rubber Factory. In 1934, they were taken over by ITT/Standard Electric, at which point it was given its new name STK. That name would remain until 1987. In 1935, after starting the producton of telephones, they had 54 people on the payroll. Between 1950 and the early 1970s, the company was expanded several times and finally employed over 4000 people. The company was based in Økern, close to Oslo.

The image on the right is an artist-impression of the factory in Økern, made in the late 1940s. It had its own bus route (25) operated by Oslo Public Transport from 1948 onwards, until it was replace by a metro line in 1966 [1].

In 1987, ITT sold STK to Alcatel, who changed the name to Alcatel Cable Norway AS. In the early 1990s, after a series of restructuring at Alcatel, almost all production facilities at Økern were closed. As a result, Oslo lost one of its last major industrial employers [2]. In 2000, Alcatel split-off most of its cable operations and established the independant Nexans company.
STK factory in Økern, Oslo (Norway)

The concrete structures at Økern are still present and in 2008 plans were afoot to convert the buildings into homes and schools. As of June 2008, the 9-story administrative building has been converted into a first-class guest house, and is now known as Quality Hotel 33 [3].

 STK cipher machines
 Thales cipher machines

STK equipment on this website
ETCRRM mixer machine used on the Washing-Moscow hotline
RACE (KL-51)
STK was well-known for a series of cipher machines they produced over the years for the Norwegian, American and NATO forces. The company started in 1955 with the production of the Electronic Teleprinter Cryptographic Regenerative Repeater Machine (ETCRRM) of which three different models were manufactured. This machine is probably best known for the fact that it was used at the height of the Cold War on the Washington-Moscow hotline from 1963 onwards [7]. Machines like the ETCRRM employ a One-Time Tape system and are in principle unbreakable.

Later developments included SELMA (Standard Electronic Letter Machine) OKA-150, a cipher machine that was developed for the Norwegian government (1960), and a transistorized version of the ETCRRM, called TCE-160 (Telecom Crypto Equipment 160), in 1963. They also developed a special machine for the production of random key tapes, known as the KTP-3 [6].

In the mid-1960s, STK made the move from One-Time Tape to machines with internal key generators, based on electronic Pseudo Random Number Generators (PRNG). The first machine in this range was the TCE-180, also known as TROL. Due to difficulties in the design, this machine never reached the production stage [5]. The name TROL was probably derived from a NATO evaluation under the same name in the early 1960s. Other companies, such as Philips, also developed TROL equipment, but they all lost the competition to the British ALVIS (BID/610).

The TCE-180 (TROL) was followed by the much improved Telex cipher machine Cryptel 240, which had such a strong encryption algorithm that the Norwegian government restricted the machine to a limited number of official users only. As the machine was not built to military standards, it wasn't suitable for the military either. As a result, not many Cryptel 240 were sold.

A year later, in 1967, the Cryptel 245 was released. It was based on the design of the Cryptel 240, but had a less advanced crypto logic, making it more suitable for civil applications. About 400 units of the machine were built, some of which were sold to oil companies and banks. Until this time, all STK cipher machines were designed by chief engineer Per Abrahamsen [5].

In 1973, STK started the development of a fully electronic military cipher machine, called RACE. It was based on the first generation of microprocessors and was released in 1978. A commercial version of RACE, with a weaker cipher algorithm, was known as Cryptel 265. In 1982, RACE was chosen by NATO and Canada as one of the machines to replace the ageing American KL-7, alongside the Philips Aroflex. The US Army also adopted the machine and called it KL-51.

The RACE/KL-51 was very robust and had a very long life span. In 2010, some of them were still in service with the US Army. STK, who was initially owned by ITT, was eventually bought by Alcatel and is currently owned by Thales. Although the name STK has disappeared, Thales Norway still successfully develops and sells cryptographic devices. All known machines are listed below.

Known STK cipher machines
  1. Wikipedia, Standard Telefon og Kabelfabrik (Norwegian)
    Retrieved October 2011.

  2. From Industrial to commercial area, Standard - an example (Norwegian)
    Website. Oslo City Archive. 2008. 1

  3. Rolf E. Wulff, Petter eroberet Økern
    Website 20 June 2008. 1

  4. Sverre A. Christensen, Switching Relations,
    the rise and fall of the Norwegian telecom industry.

    Dissertation submitted to BI Norwegian School of Management. 2006.
    ISBN: 82-7042-746-2.

  5. Frode Weirud, Crypto Historian, Personal correspondence
    Crypto Museum, June 2012.

  6. Leif Nilsen, NISnet Kick-off
    Thales Norway AS, PowerPoint presentation. 10 October 2007. Retrieved June 2012.

  7. Norwegian National Security Authority (NSM), Årsmelding 2008
    NSM Annual Report 2008 (Norwegian). Noen kryptosuksesser. p. 15.

  8. Hugo Ryvik, On a Secret Mission, 50 years of Norwegian cryptology
    2005. Thales internal publication. Limited edition.
  1. Website no longer available in October 2012.

Further information
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