Dr. Edgar Gretener AG, Zürich Altstetten
Gretag AG, Regensdorf
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überarbeitet am 20.6.2014

The Dr. Edgar Gretener AG has been founded at Zurich - Altstetten in 1943, they started business with a video projection system called "Eidophor" developed together with Ciba.

After Dr. Gretener deceased, the company has been renamed Gretag AG in 1958; and the companies headquarters were relocated from Kleinstrasse, Zurich to new premises in Regensdorf ZH, where Gretag resided for many years. They developed automatic encryption systems as well as a colour separation system for the printing industry.

One of the first developments was the famous ETK, Einton - Kombinationsschreiber, a combined letter printer. In contrast to the standard teletypewriter Baudot code, this machine used a special code combining one letter from several out of fourteen different segments, which made message transmission more reliable, as letters remained still legible, even if one or two of the segments were missing.
After he had settled down in Switzerland, the famous inventor of ciphering machines Boris Hagelin, who had been living in Sweden before, had a short time of cooperation with Edgar Gretener in 1948, before he founded his own company "Crypto AG" located at Zug in 1952, which is still in business today.
The Gretag developed a automatic ciphering machine matching the fourteen segment ETK printer shortly after, this was the automatic cipher machine Telecrypto 53, transmission quality was quite reliable over telephone lines - when wireless connections were used, the automated encryption lost synchronisation quite often, when the shortwave communication suffered from fading.
This situation became much better, when Gretag came out with the very much improved Kryptofunkfernschreiber KFF, which provided automatically encrypted radioteletype transmission with automatic synchronisation, specially in connection with Zellweger's compact SE-222 single sideband transceiver.
Any machines using the ETK fourteen segment code remained without commercial success outside Switzerland, Gretag developed the Telecrypto 61 ciphering teletype messages using the Baudot code.
Later on, Gretag produced a large number of electronic ciphering devices called "Gretacoder"

In the early nineties, the cryptology segment of Gretag AG has been split off and became Gretag Data Systems, in 1995, it changed name to become Gretacoder Data Systems AG.
The company has been taken over by an American investor and changed name for Safe Net Data Systems AG, even with some new investments, this company did not survive and ceased operation in late 2004.
Most patents of Greacoder AG went into possession of Omnisec, this company was also resident at Regensdorf ZH.

further literature:
d/e: Gretener AG / Gretag at www.radiomuseum.org
e: Gretag at www.cryptomuseum.com

© Martin Bösch, 26. Dez. 2011