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Online one-time-tape ciper machine

ULES-64 was an electronic One-Time Tape (OTT) cipher machine for encryption and decription of telegraphy signals (telex), developed around 1964 by Crypto AG (Hagelin) in Zug (Switzerland). As the devices were theoretically unbreakable — they were based on the One-Time Pad (OTP) — they were only supplied to friendly nations and were not advertised in Hagelin's public brochures.

The machine measures xx x xx x xx cm nd weights approx. 50 kg. It has two tape readers at the top surface – one for the message and one for the key tape – and is only suitable for off-line use.   

ULES-64 marks Crypto AG's transistion from electromechanical OTT cipher machines to fully electronic ones.

At present, not much is known about the ULES-64, as they do not show up in any of the the Hagelin/Crypto AG brochures in our archive. The machine shown above was used for many years by the Dutch Ministry of Foreign Affairs for contact with its embassies abroad. They were used alongside other mixers, such as the Philips Ecolex II and Ecolex IV, for messages of the highest level of secrecy.

Like most other ULES-64 machines, the one shown here has undergone a few modifications over time. The most abovious one is the replacement of the carrying handles at the sides. As the original hinged ones were not strong enough to carry the rather heavy machine, they were replaced by strong window grips from a local hardware store.

Another problem with the ULES-64 was related to temperature. As the device is built with the first generation Integrated Circuits (ICs) based on the so-called Transistor-Transistor-Logic (TTL), is generates a lot of heat. For this reason, the back panel was often replaced by a metal grid, so that the internal parts had sufficient cooling. So far, we have recorded the following modifications:

  1. New carrying handles at the sides
  2. Rear panel replaced by metal grid
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Crypto Museum. Created: Friday 26 October 2018. Last changed: Sunday, 23 December 2018 - 14:12 CET.
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