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Oskar Stürzinger   SIGFRIED
Chief developer at Crypto AG

Oskar Stürzinger (5 December 1920 - 23 July 2011) was an engineer of (electro)mechanical cipher machines. In the late 1940s he worked for Swiss inventor Dr. Edgar Gretener (later: Gretag) in Zürich (Switzerland), where he was (partly) responsible for the development of the ETK teleprinter and the TKG-35 cipher machine — a joint development of Dr. Edgar Gretener and the Swede Boris Hagelin. In 1952, when Hagelin moved his business from Sweden to Switzerland, Stüzinger and his wife Emmy were the first two employees of Hagelin's newly established company Crypto AG.

Stürzinger was born on 5 December 1920 in Winterthur-Töss (Switzerland) and was educated in the early 1940s as an Electro-Engineer at the ETH in Zürich. After his graduation he started working for inventor Dr. Edgar Gretener, where he became involved with the development of the proprietary ETK-47 teleprinter and a new cipher machine, the TKG-35, that was jointly developed with Boris Hagelin of AB Cryptoteknik in Sweden.

The cooperation between Gretener and Hagelin didn't last, and the latter decided to move his business from Sweden to Zug in Switzerland.
Oskar Stürzinger on 8 November 2008 in Basel (Switzerland)

In 1950, Hagelin – tired of the restrictive Swedish export regulations and the high tax burden – founded a Swiss company, Crypto AG, of which the ownership was carefully hidden from view, by using a complex structure of foundations in tax paradise Lichtenstein. In 1952, he moved most of his Swedish business to the new Crypto AG in Zug (Switzerland) and persuaded Oskar Stürzinger to become his first employee. Stürzinger accepted and would eventually become chief developer.

Personal life
Stürzinger's wife, Emmy, was the second employee of Crypto AG and became a secretary. Under plant manager Sture Nyberg, who had been the director of the Stockholm factory, business was growing and new personnel kept flowing in. In 1966, the company moved to a new premises in Steinhausen and Stürzinger developed a random generator for the creation of random tapes.

During the 1950s and 60s he was arguably the most important engineer at Crypto AG as he was able to converted Hagelin's mechanical designs and ideas into practical products. But by the late 1960s it became clear that the days of the mechanical cipher machines were numbered and that the company soon had to make the transition to electronic cipher machines that were based on shift registers. In 1970, the company was sold and Boris Hagelin retired. In the early 1980s, his wife Emmy died and a few years later he retired as well. He moved to Monte Carlo but kept a holiday home in Switzerland. In 1998, he lost his only daughter in a plane crash in Halifax.

Rigged machines
In 2008, Crypto Museum curators Marc Simons and Paul Reuvers had the honour to meet mr. Stürzinger – then 88 years old – in person in Basel (Switzerland) at the presentation of Domink Landwehr's book Mythos Enigma. For the event, Stürzinger had brought several items from his private collection and from the internal collection of Crypto AG, and insisted on making a presentation on the history of cipher machines and that of Boris Hagelin in particular [4].

In the evening we had the chance to have a private conversion with Oskar and came to speak about the recurring rumours that Crypto AG equipment was rigged so that they were readable to western intelligence agencies. Stürzinger confirmed that the company was frequently visited by foreign experts, who influenced the cryptographic algorithms that were used in CAG equipment.

These visits started in the 1970s and continued until at least the mid-1980s, when Sturzinger retired. Although he had no direct proof, he assumed that the foreign experts – who presented themselves as Intercom Associates employees – were in fact specialists from the US National Security Agency (NSA). He appeared to be frustrated because he — the first Crypto AG employee and for many years head of the development department — was not made aware of the purpose of the expert visits. To him, this confirmed that the company was under foreign control.

The real owners
In February 2020, the German TV station ZDF and the American newspaper Washington Post, revealed the true story behind Crypto AG, the company for which Stürzinger had given the best 30 years of his life [3]. In the program it was revealed that in 1970, Boris Hagelin had sold his company to a joint venture of the German Bundesnachrichtendienst (BND) and the American Central Intelligence Agency (CIA), in a deal that is called the intelligence coup of the century.

In a carefully plotted script that was known as Operation RUBICON, BND and CIA had created the legend that Siemens was the actual owner of the company, but that no one was supposed to know that. In reality however, BND and CIA were the owners and controlled the company through a complex web of companies and advisory boards [3]. CAG-personnel, including Stürzinger, was completely unwitting of this. For the CIA – who gave him the codename SIGFRIED – Stürzinger was no more than a fossil from a bygone era, and making him witting would have been a security risk.

Minutes of a secret meeting held at Motorola on 19-20 August 1975 at which Oskar Stürzinger represented Crypto AG [7]

Nevertheless it is very likely from surviving documents [6], that Stürzinger was fully aware of the influence that NSA, CIA, BND and others had on the company. As he was Hagelin's first employee in Switzerland, and had been head of the development team for many years, it is likely that he had been briefed by Hagelin at a very early stage. This is supported by the fact that his name appears on the minutes of a secret meeting held at Motorola on 19-20 August 1975 (see above) [7]. To our surprise, Herb Frank (CIA) and Nora Macabee (NSA) were both present under their real names, although they were pretending to represent the fake company Intercom Associates (IA).

 More about Operation Rubicon

On 23 July 2011, Stürzinger passed away quietly in his house in Monte Carlo (Monaco) at the age of 91 [9]. Swiss historian Dominik Landwehr, who had built a close friendship with Stürzinger over the years, wrote an affectionate In Memoriam about him [1].

The video clip below shows Oskar Stürzinger demonstrating the CD-57 pocket cipher machine to a crypto lecture audience in Switzerland on 17 August 2002 [4].

  1. Chiffriertechnik Heute - Krieg im Aether
    Oskar Stürzinger, ETH Zürich, 1976/1977.
  1. Dominik Landwehr, In Memoriam Oskar Stürzinger (1920-2011)
    Retrieved August 2013.

  2. Crypto Museum, The Gentleman's Agreement
    15 July 2015.

  3. Crypto Museum, Operation RUBICON
    February 2020.

  4. Paul Reuvers & Marc Simons, Interview with Oskar Stürzinger
    Basel (Switzerland), 7 November 2008.

  5. Dominik Landwehr, Über Kryptografie sprach man nicht - Oskar Stürzinger...
    Sternenjäger, 15 February 2020 (German).

  6. Crypto Museum, Operation RUBICON
    February 2020.

  7. Scott Shane & Tom Bowman, Spy sting: Few at the Swiss factory knew...
    Baltimore Sun, 10 December 1995.

  8. Dominik Landwehr, 2002 - Oskar Stürzinger erklärt die Crypto CD-57
    17 August 2002.

  9. Dominik Landwehr, Personal correspondence
    16 August 2011.
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