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Gretacoder Data Systems

Gretag, or Gretacoder Data Systems, was a fully independent manufacturer of cryptographic equipment, based in Regensdorf near Zürich (Switzerland). It was founded by Dr. Edgar Gretener who was not only a direct competitor of Boris Hagelin, but also worked with him on a number of occasions. The company, which also made the encryption devices for international SWIFT bank transactions, had a world-wide customer base and had once over 2500 people on its payroll.
Gretag company logo

Over the years, Gretag produced a range of commercial, industrial and military cipher machines. It is known that American intelligence (NSA, CIA) tried to get control over the equipment that was produced by Gretag, but to no avail. As a result, Gretag was regarded a serious threat. Although the NSA was able to break most of the early machines, they were not able to read 1 more than 7% of the traffic encrypted on Gretag cipher machines that were produced in the late 1970s [20].

The West-German Bundesnachrichtendienst (BND) also had a keen eye on Gretag, and regarded the company as their most serious threat. Unlike its main competitor – Crypto AG – it was not under control of the CIA and BND, which meant that their cryptographic algorithms could not be rigged. For several years, the BND tried to get a grip on the engineers and even tried to buy the entire company from its owner Ciba-Geigy, but to no avail. Gretag remained unreadable to them [20]. It is known that the BND launched several smear campaigns against Gretag, in the hope that potential foreign customers would instead choose Crypto AG, which was owned by BND and CIA.

The US Central Intelligence Agency (CIA) was more successful, and got the American telephone company AT&T to take over the company in 1991. This gave the CIA full control over the crypto algorithms, and also over the equipment that was used for the SWIFT banking network. The international governmental business had already been passed to the the Swiss company OmniSec in 1987 [17]. Eventually, the Gretag business – by then part of SafeNet – was liquidated in 2004.

 Gretag cipher machines

  1. In this context, readable means that the cryptographic algorithms could be broken by the NSA. Also known as friendly. In contrast: algorithms that are not breakable by NSA, are called unfriendly or unreadable.

Below is a brief summary of the history of the company, in particular with respect to the development and production of cipher machines. For a chronological overview of important events in the history of the company, we have added a timeline at the bottom of this page.


Dr. Edgar Gretener AG   1943
Gretag AG started life around 1943, when its founder, Dr. Edgar Gretener established Dr. Edgar Gretener AG in Zürich (Switzerland). Gretener was one of the developers of the famous Eidophor large screen video projector that was later marketed by his company [22]. He became famous for a series of hi-end cipher machines he developed for the Swiss Army, and for his wide range of colour image processing equipment for the printing industry. All equipment manufactured in the early years carried the name of the founder: Dr. Edgar Gretener AG.

Cipher Machines   1946
In 1946, the company started the development of teletypewriters (telex) and cipher machines. In 1947, a small lightweight teleprinter, called the ETK-47, was succesfully introduced and it wasn't before long that it became widely accepted by the Swiss Army and by small businesses. In 1949, the Swiss Army expressed an interest in online cipher machines, resulting in a brief cooperation between Dr. Edgar Gretener and the Swede Boris Hagelin, who would later become his competitor.

The result of this joint development was the so-called Telekrypto-Gerät 35, also referred to as the GR tg 35, TKG or TC-35 [8]. In 1951, 35 of these TKG machines were delivered to the Danish Army [9]. The machine formed the basis for the development of later cipher machines such as the TC-53 that was designed to work with Gretener's proprietary ETK-47 teleprinter.

Apart from Dr. Edgar Gretener himself, the key developer of the cipher systems was Kurt Ehrat who had joined the company on 1 April 1946 [10]. In the following years, many of the crypto-related patents would be registered in his name.

The cooperation with Hagelin was not restricted to the Telekrypto 35, but dates back to 1947, shortly after Gretag had introduced the ETK-47 teleprinter. Hagelin was particularly interested in these teleprinters, as they were suitable for his foreign customers. As the ETK uses a proprietary 14-bit technology to build a character from the (14) individual segments, it can be modified easily for foreign languages, such as Russian (Cyrillic), without replacing the print head [12].

Gretag AG   1958
After Dr. Edgar Gretener's untimely death on 22 October 1958, the company was taken over by the Swiss chemical company CIBA Holding AG (now: Novartis) who changed the name to Gretag AG. Dr. Robert Käppeli, one of Gretener's finiancial backups, became the new director [7].

Shortly afterwards, the company moved to Regensdorf (near Zürich), where CIBA had secured a large new premises on an industrial estate that provided room for expansion. In the following years new buildings were added and eventually the company would employ over 2500 people. Even today (many years after the demise of Gretag) the area is known as the Gretag-Areal [14].

In 1959, the sales of the Eidophor large screen projectors was spun out of the company, and moved to the new company EIDOPHOR AG — a joint verture between Gretag AG and Philips.

Business groups   1962
By 1962, the company produced over 100 different products in a wide variety of fields, including cipher machines, but also devices for the (colour) printing industry. As this was confusing — not only for the employees but also for the customers — CIBA decided to divide the many products into product categories, each of which was supported by a business group [15]:

  1. Arc lamps
  2. Eidophor
  3. Teleprinters, Cipher Machines, electronic devices
  4. Projection screens
  5. Digital technology
  6. Various
  7. Copiers
At this point, Dr. ter Meer was the director of Gretag AG. As part of the takeover by CIBA, all former Gretag patents were moved to CIBA, who also managed and monitored them. Some of the early patents were dropped and some other patents were eventually given back to Gretag AG.

Patent Wars   1971
By the late 1960's, Gretag held a respectable number of world-wide patents, most of which were related to Gretag's ever increasing photographic reproduction business. Nevertheless, the name of Kurt Ehrat, head of the cipher equipment development, appears 6th in the list of people with at least five cryptographic patents in the US, just one place below the famous William Friedman [16].

In the early 1970s, it became increasingly difficult to register new patents as many inventions were declared invalid due to prior art in a number of countries. In the photographic business there was a stiff competition with renowned companies like AGFA, KODAK, Fox-Stanley and CA Pieronex, resulting in legal claims from these companies, and counter-claims from Gretag.

In the US, it appeared to be very difficult to register patents related to high-end electronic cipher equipment — such as the TC-803 and TC-812 — because of the Secrecy Act of the Department of Defense. This required the patents to be secret and blocked the sales of such machines to the general public. For that reason the patents were not filed in the US, but only in Canada and Japan.

Nevertheless, Gretag kept filing new patents in a variety of fields, and by 1976 they had well over 100 patents in their card index. Head of cryptographic developments Kurt Ehrat was arguably the most active cryptographic inventor in the company with 23 crypto-related patents in his name, whilst Robert Wahli was the number one with 39 patents, mainly related to the photo-business.

Omnisec   1987
In the late 1980s it became clear that Gretag's product range was far too diverse. Although the crypto-related business was a significant one, and many new systems had been introduced over time, it was overshadowed by the photographic business. In addition, the crypto-business was often linked to secrecy, espionage and doubtful regimes, and the owner – CIBA – felt increasingly uncomfortable with that. There was also pressure from Western intelligence services. On at least one occasion, the BND had tried to buy Gretag, and there was also pressure from the CIA [20].

In June 1986, CIBA instructed the Gretag board of directors to find a buyer for the business group 'Authorities' which handled the sales of strategic equipment to foreign governments and armies. In June 1987, the board announced that the business unit would be transferred to the newly established OMNISEC, also in Regensdorf.

OMNISEC had been founded especially for this purpose and was fully owned by the all-Swiss ARGONIUM SA, a high-tech holding consortium in Geneva. The new company was led by Dr. Pierre Schmid, a former employee of Gretag AG.

After leading the development of cipher machines for many years, Schmid had left Gretag in 1978 to start working for Standard Telephone und Radio AG (STR) in Zürich, the Swiss subsidary of the American ITT. At least 7 crypto-related patents were registered in his name during his time at Gretag [18]. Approximately 10 Gretag employees were given the option to make the switch to OMNISEC as well, mainly people from the Intelligence Technology section. In July 1987, Gretag's customers were informed and OMNISEC officially started trading on 1 October 1987 [21].

With the transfer, OMNISEC acquired the production rights of all Gretag cipher machines, with the exception of the civil cipher machines GC-517, GC-518, GC-519 and GC-715, and the machines for the Swiss authorities (GRD). OMNISEC was allowed however, to offer the civil machines abroad as OEM products. Initially the OMNISEC machines were still manufactured at Gretag, but over the years, production was gradually moved over to OMNISEC's own facilities. Although OMNISEC was successful in the next 25 years, the company closed its doors in 2018 due to lack of orders.

 More about OMNISEC

AT&T / Gretag Data Systems   1991
Being left with just the civil crypto-market, such as banks and the Swiss Government, the cipher machine division of Gretag AG became less and less significant. As a result, CIBA finally decided to split-off the cipher-business altogether, and sold it in 1991 to the large American Telecom provider AT&T. The former business unit became a new legal entity: Gretag Data Systems AG.

Many of the systems developed in the following years, such as the Gretacoder 524, would carry the brand name Gretacoder, or AT&T, or both. With the acquisition, AT&T had hoped to get a foot in the Swiss market and get access to systems for safe bank transactions at the same time. It didn't work out well however, as there was strong competition from companies like Crypto AG (Hagelin) and former Gretag-split-off Omnisec AG. In comparison to AT&T's business in the US, the Swiss operation appeared to be minute and AT&T gradually lost interest.

IRE / Gretacoder Data Systems   1995
In October 1995, the company was acquired by Information Resource Engineering Inc. (IRE), a US company that had been established in 1987 by two former NSA Engineers. Gretag Data Systems, which had a turnover of $7 million in 1994, was bought for approx. $4 million [4] and the name was subsequently changed to Gretacoder Data Systems AG. Many new encryption devices were produced during this period, all of which carried the brand name Gretacoder.

SafeNet Data Systems   2002
In 1999, the current owner of the company – IRE – was renamed to Safenet, after its VPN product line. A few years later, in 2002, Gretacoder Data Systems was renamed to Safenet Data Systems [6]. Due to domestic and international competition, the Gretacoder business was rapidly declining and SafeNet injected signficanly new capital in an attempt to turn the tide.

 More about SafeNet

Demise   2004
Despite the new capital injections, the company did not survive. Finally, late 2004, the board of directors saw itself forced to announce immediate liquidation of the company.

The former Gretag buildings at Althartstraße in Regensdorf are still standing today and still carry the name of the once so large company. The estate is now called Gretag-Areal and the buildings are rented in small units to a wide range of different companies [14]. Gretag-Areal is headed by Felix Ruhier, who was once a Group Controller at Gretag (1991-1993) [19].

Company logo
When Dr. Edgar Gretener founded his company in 1943, there was no official company logo, and all official documents, offerings, brochures, etc., were signed with the name Dr. Edgar Gretener Aktiengesellschaft. In the late 1940s, the first official company logo appeared, as shown above.

It is basically a monogram with the initials of Dr. Edgar Gretener – EG – merged into a circle. The image on the right shows an original cliché of 1957, that was used for printing the company's stationary and the front pages of the manuals.   

In 1958 – after Gretener had passed away unexpectedly – the company was sold to CIBA Holding AG and the name was changed to GRETAG AG. At the same time, the old monogram-logo was replaced by the word 'GRETAG', printed double-spaced in a Palatino typeface, as shown below.

In the late 1970s the name GRETACODER was introduced and the company name on some of the brochures was changed to GRETAG COMMUNICATIONS SECURITY, printed in a Futura-ExtraBold typeface, accompanied by an uninspiring blue logo of a punched paper tape with a curly arrow.

In the following years, probably in the mid-1980s, the logo above was replaced by a stylized line-art drawing of a blue cubical G with the word GRETAG printed below it in a hand-crafted angular typeface. This is the final logo that was used until the demise of the company in 2004.

Official design of the Gretag monogram
Cliché of Gretag monogram
Cliché of Gretag monogram
Cliché of Gretag monogram
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Official design of the Gretag monogram
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Cliché of Gretag monogram
3 / 4
Cliché of Gretag monogram
4 / 4
Cliché of Gretag monogram

Below is an overview of important events in the history of Gretag in chronological order. It also highlights some of the attempts of foreign intelligence agencies – in particular CIA and BND – to get control over Gretag. Given the context in which the events took place, it seems reasonable to assume that the take over of Gretag by AT&T in 1991, was orchestrated to put the CIA in control.

Known addresses
Gretag, or Gretacoder Data Systems AG, is no longer in business and support for old Gretag equipment is non-existent. The last known addresses are:

  • Dr. Edgar Gretener AG (1943)

  • Gretag AG (1958)
  • Gretacoder Data Systems AG (1995)
  • SafeNet Data Systems AG (2002-2004)
    Althartstrasse 150
    8105 Regensdorf

  1. Gretag full-colour company brochure
    October 1969. 16 pages.
  1. Ulrich Rimensberger, Datensicherung durch Chiffrierung
    Description of the Gretacoder 515, published at the 5th International Congress for Data Processing in Europe. Vienna, 21-25 March 1977.

  2. Gretacoder Data Systems AG. Gretacoder 650, High-Speed Link Encryptor.
    2-page sales brochure. August 2000.

  3. Gretacoder Data Systems AG. Gretacoder 545, X.25 Data Encryption.
    4-page sales brochure. April 1997.

  4. The Free Library, IRE Acquired Gretag Data Systems AG
    11 June 1995, Retrieved march 2012.

  5. Dr. John H. Nugent, Curriculum Vitae
    Member of Board of Directors at AT&T Gretag 1991-1993.
    31 March 2007. p. 6. Retrieved March 2012.

  6. Business Wire, SafeNet to Expand and Strengthen European Operations...
    Business Library website. Retrieved July 2012.

  7. Wikipedia Germany, Edgar Gretener
    Retrieved May 2013.

  8. Dr Edgar Gretener AG, Telekrypto-Gerät GR tg 35
    Gretag Archives, 1949-1951. Crypto Museum #CM301792.

  9. Gretener AG, Besprechnungsnotiz vom 30. März 1951
    Minutes of meeting concerning delivery of 35 TKG machines to Danmark (German).
    Gretag archives, 3 April 1951. Crypto Museum #CM301792/A.

  10. Gretag AG, Personalmutation Kurt Ehrat
    Interial memo about Kurt Ehrat reaching retirement age (German).
    Gretag Archives, 31 January 1979. Crypto Museum #CM301766.

  11. Schweizerische Bauzeitung, Edgar Gretener. 3 March 1957 - 22 October 1958.
    Obituary (German). 76th edition, Volume 51. 20 December 1958.

  12. Letter from [Oskar] Stürzinger (Hagelin) requesting Cyrillic characters for the ETK-47
    21 March 1947. Retrieved from [13].

  13. Walter Schmid, Der Krypto-Funk-Fernschreiber KFF-58
    October 2008.

  14. Gretag Areal, Regensdorf, Zurich 1
    Website of the current land owner of the former Gretag buildings.
    Retrieved July 2013.

  15. CIBA AG, Aufteilung der Gretag-Cases in die verschiedenen Sachgebiete
    Creation of Gretag operational divisions (German). Gretag Archives.
    Basel, 17 December 1962. Crypto Museum #CM301793.

  16. US Patent Office, List of inventors with at least five (cryptographic) patents
    Date unknown, but likely to be 1968.

  17. Gretag AG, "Leitfaden" zur Info-Weitergabe am 29.7.87
    Memorandum about the transfer of cipher equipment to OMNISEC AG (German).
    29 July 1987. #CM301765/A.

  18. Crypto Museum, Gretag AG Patents
    Complete overview and correspondence regarding Gretag Patents 1943 - 1990.
    Gretag Archives, Crypto Museum #CM301767.

  19. Linked-in, Felix Ruhier
    Retrieved July 2013.

  20. Paul Reuvers and Marc Simons, Operation RUBICON
    Crypto Museum, 19 March 2020.

  21. Gretag & Omnisec, Announcement to customers and agents
    29 July 1987. #CM301765/B.

  22. Wikipedia, Eidophor
    Retrieved November 2020.
  1. This website is now defunct.

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© Crypto Museum. Created: Thursday 05 July 2012. Last changed: Sunday, 14 January 2024 - 17:41 CET.
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