Click for homepage
← Crypto
Switzerland
  
Gretag
Gretag, or Gretacoder Data Systems, or simply Gretacoder, was a 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

Gretag produced a range of commercial, industrial and military cipher machines, that were of a remarkable quality and were not rigged by foreign intelligence services like CIA or BND, although the latter two tried to get their hand on Gretag on several occasions. In 1991, the company was eventually taken over – under control of the CIA – by AT&T, and liquidated in 2004 – when it was owned by SafeNet. Before the takeover however, most of the patents had already been transferred to Omnisec AG - a new Swiss company that had been created especially for that purpose. More...

Gretag's cipher machines are known under different names and numbers. Generally speaking, the numbering was never changed, but different prefixes and brand names were used. The name Gretacoder was sometimes abbreviated as 'GC' or 'TC' (for: Tele-Crypto, or Teleprinter Crypto). E.g.: the military 812 telex encryption unit is known as Gretacoder 812, GC-812 and TC-812.

 More about Gretag


Gretag cipher machines on this website
Telekrypto-Gerät 35, developed by Edgar Gretener (Gratag) and Boris Hagelin. One of the first electro-mechanical cipher machines build by Gretener Electronic military telex encryptor Electronic military telex encryptor Gretacoder 101, speech scrambler Gretacoder 103, telephone scrambler Gretacoder 104, voice scrambler TC-803 electronic portable off-line teletype encryptor
Gretacoder 805 (portable version) Gretacoder 805 (desktop version) Gretacoder 905, portable electronic cipher device Gretacoder 519 Fax Encryptor (Facsimile Cipher Unit) Gretacoder 521 for Haslter SP-300 teleprinter Gretacoder 524 link encryptor (64 kb/s) Gretacoder 603 bulk encryption device Gretacoder 605 link encryptor (2048 kb/s)
Gretacoder 715 Message Authenticator Gretacoder 720, extremely secure DES encryptor for SWIFT transactions Schlüsselproduktionsgerät (key production device)
SPG
Digital circuit blocks
TKG 35   wanted item
Telekrypto-Gerät 35 (TKG) was an online cipher machine for Gretag's proprietary 14-bit teleprinters, such as the ETK-47. It was a joint development of Dr. Edgar Gretener (Gretag) and competitor Boris Hagelin and used Hagelin's pin-wheel system.

 More information
  

TC-53
The TC-53 was the first electro-mechanical cipher machine manufactured by Gretag for the Swiss Army. It was based on an earlier design of Dr. Edgar Gretener and competitor Boris Hagelin.

The machine had 12 cipher wheels and used a novel 14-bit technique, rather than the usual 5-bits for transmission of the data.

 More information
  
TC-53 without the SPG key generator

TC-534
In 1964, Gretag made the move to electronic cipher machines, with the development of the TC-534. It was a military device that consisted of two large watertight boxes, and was built with in-house developed digital building blocks.

 More information

  

TC-803
Around 1970, Gretag introduced the first fully electronic portable cipher machine for teletype signals. The device was housed in a standard Samsonite briefcase and was intended for by the intelligence and diplomatic community.

The device was later found to be insecure as it uses linear-feedback shift registers (LFSRs), after which it was succeeded by the Gretacoder 805.

 More information

  
Gretag TC-803 cipher machine with strip printer

TC-850
In the mid-1970s, Gretag developed an all-in-one electronic cipher machine for teletype signals, aimed to the replace the KFF/TC-58 which used the (meanwhile) obsolete ETK tele­printer technology.

 More infomration

  

Gretacoder 101
The Gretacoder 101, or GC-101, was a modular speech scrambler for telephone and radio links, introduced in 1975. It uses two-dimensional voice scrambling and was based on the earlier SC-101 from 1973.

The device is suitable for half-duplex only, which is controlled by a Push-To-Talk (PTT) switch in the handset.

 More information
  
Gretacoder 101

Gretacoder 103
The Gretacoder 103, or GC-103, was a voice scrambler for analogue telephone lines. It is inserted between the phone and the line.

It uses time-domain as well as frequency-domain scrambling and was manufactuered as an OEM product by Telsy in Italy. It is identical to the Telsy TDS-2004.

 More information
  
Telsy TDS-2004

Gretacoder 104
The Gretacoder 104, or GC-104, was a voice scrambler for mobile use. It uses time-domain as well as frequency-domain scrambling and was manufactuered as an OEM product by Telsy in Italy. It is identical to the Telsy TDS-2004M.

 More information
  
TDS-2004M

Gretacoder 805   portable
The Gretacoder 805 was a small portable electronic cipher machine that was fitted inside a standard Samsonite briefcase, together with a small thermal printer.

 More information
  
Gretacoder 805

Gretacoder 805   desktop
As the Gretacoder 805 had a highly modular design, a variety of different configurations were possible. For the office, a large desktop version could be created, complete with a papertape reader/puncher ans shown here.

 More information
  
Complete Gretacoder 805 desktop system with paper tape reader/puncher on the left

Gretacoder 905
Gretacoder 905 was the first fully-electronic portable cipher machine, produced by Gretag in 1976. It has a display with 32 LEDs and features just three push-buttons and one rotary switch.

The GC-905 was a direct competitor of the Hagelin HC-520.

 More information

  

Gretacoder 519
Gretacoder 519 was one of the first fax encryption devices on the market. It was introduced in 1984 and was inserted between a modem and the actual fax machine. It was suitable for speeds up to 9600 baud.

 More information
  
GC-519 in desktop enclosure

Gretacoder 524
Gretacoder 524 was a line encryptor for synchronous (RS-232) serial links, developed in the early 1990s when Gretag was part of AT&T. It supports continuous data encryption at rates up to 64 kb/s and was available with various interfaces and (software) options.

 More information
  
Gretacoder 524

Gretacoder 603
This 19" rackmount system, consisted of two units. One for either side of the communication link. It was used to encypher and decypher multiplexed data streams over satellite links.

 More information
  

Gretacoder 605
Gretacoder 605 was a line encryptor for synchronous (RS-422) serial links, developed in the mid-1990s when Gretag was part of IRE (Now: SafeNet). It supports continuous data encryption at rates up to 2048 kb/s and was available with various interfaces and options.

 More information
  
Gretacoder 605

Gretacoder 720
Gretacoder 720 was a highly secure DES encryptor for international bank-to-bank payments (SWIFT). It was housed in a large strong 19" case and was highly tamper-proof.

 More information
  
Gretacoder 720

Known Gretag equipment
Below is a non-exhaustive list of the various Gretag devices we've identified so far. Initially all cipher machines were built under the Gretag brand. Later the name was changed to Gretacoder, which was sometimes abbreviated as 'GC'. In the overview below, 'GC' stands for Gretacoder, whilst 'TC' stands for 'Tele Crypto' or 'Teleprinter Crypto'. Found another one? Please let us know.

Encryption devices
Photo equipment
  • D-1
    1965
    Densitometer
  • CGC-501
    1965
    Coulometer
Other
Documentation
  1. Gretag full-colour company brochure
    October 1969. 16 pages.

  2. Sales leaflet, Gretacoder Security Systems
    Gretag AG, September 1979.
References
  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. Walter Schmid, Der Krypto-Funk-Fernschreiber KFF-58
    October 2008.
Further information
Any links shown in red are currently unavailable. If you like the information on this website, why not make a donation?
© Crypto Museum. Created: Thursday 06 August 2009. Last changed: Thursday, 27 February 2020 - 22:32 CET.
Click for homepage