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Secure crypto telephone - wanted item

TCE-500 is a secure narrow-band telephone set for use on standard analogue networks (PSTN), developed by Thales Norway (previously: Thomson CSF, Alcatel and STK) in 1993. The TCE-500 and the TCE-500B are approved by NATO for all level of classification and have a built-in modem.

The image on the right shows a typical Thomson TCE-500 unit, which resembles an ordinary telephone set. A Crypto Ignition Key (CIK), which is used for the protection of data and keys, is inserted at the rear right. A nice sample of this telephone is on display at the NCM (USA). 1

For speech encoding, the TCE-500 uses CELP at 7200bps and LPC-10 at 2400bps. As it uses the SAVILLE encription algorithm [2], it is backwards compatible with the American STU-II, the later Motorola STU-II/B and the Philips Spendex 40.

Keys are normally loaded from an external KDC 2 on a per-call basis, but can also be loaded with a key fill device or manually via the keypad [2].

A civil version of the TCE-500 is known as the TCE-520. Although both models look identical, the TCE-520 is not compatible with the American STU-II and is not NATO-approved. The TCE-500 can be used in combination with the TCE-550 Key Distribution Center (KDC). For the civil version (TCE-520), the TCE-560 KDC was available. We currently have no further information about the TCE-500. If you have any additional information — or better: a spare unit — please contact us.

  1. NCM = National Cryptographic Museum, the NSA's museum at Fort Meade.
  2. KDC = Key Distribution Center.

The TCE-500 was developed when the former STK assets were owned by Alcatel. Early TCE-500 units therefore carry the Alcatel logo. Alcatel was eventually taken over by Thomson CSF, which later was renamed to Thales. It is therefore possible to find TCE-500 units under different names:

Technical specifications
  • 2 or 4 line full-duplex operation
  • DTMF or pulse-dialling
  • CELP speech encoding 7200 pbs (auto fallback to 4800/2400 bps)
  • LPC-10 speech encoding
  • Data V.24, 1200, 2400, 4800 and 9600 baud
  • Tempest: ASMG-720
  • Compatibility: STU-II and compatible devices
  • PSU: 20-250V (auto-range), AC/DC, 8W (operation), 4W (standby)
  • Dimensions: 110 x 308 x 248 mm
Cryptographic algorithms
  • Alcatel proprietary
  • Customer specific
The TCE-500 is interoperable with the following devices:

  1. NATO Information Assurance, TCE 500B
    Last updated 13 July 2010. Retrieved June 2012.

  2. Jane's Military Communications, TCE 500/TCE 520 Secure Telephone
    ISBN 0-7106-1163-3. Fifteenth Edition, 1994-1995. p. 532.

  3. Thomson-CSF, TCD 500/B - Narrow Band Secure Terminal for Voice and Data
    Brochure, 4 pages. Date unknown.
Further information
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Crypto Museum. Last changed: Saturday, 24 February 2018 - 20:55 CET.
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