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E-20   E-20M
Secure voice and data terminal - this page is a sub

E-20 (later: E-20M) is a cryptographically protected telephone set for analogue PSTN networks, developed around 2005 in Russia. The device is suitable for secure voice and data traffic over insecure networks, as speeds of 2500, 4800 and 9600 baud. The 256 bit encryption key is stored on an external Data Key K1634DK6 or K1634DK4 device, that has the shape of a physical key [1].

The device has the appearance of a regular desktop telephone set. At the top is a Liquid Crystal Display (LCD). Just below it is keypad with 12 buttons, plus 7 additional buttons for navigation through the menus. TO the right of the keypad are 16 buttons for quick access to frequently dialled numbers or internal lines.

At the right side of the device is a receptacle for a Data Key K1634DK4 (К1634ДК4) key storage device that acts as a Crypto Ignition key (CIK). Secure traffic is only possible when the CIK holds a valid key and is inserted into the E-20 (E-20M).

The key storage device is very similar to the KSD-64 that was used with the American STU-III crypto phones, and was made by the same company. The E-20(M) is compatible with the E-34 and M459-1S (М459-1С) bulk encription equipment. The equipment is supplied by BNTI in Moscow — a company formed by reserve officers of the Russian intelligence service FSB. A battery-powered version of the E-20, housed in an unobtrusive briefcase is known as the E-57.

 More about BNTI

Below is an overview of the features of the E-20. The device has the size of a regular executive telephone set with 16 speed dial keys at the right hand side. At the upper edge is an LCD. At the centre is a regular DTMF keypad with the digits 0-9 plus * and #. Directly above it, are the keys for selecting the mode of operation (clear/crypto) and the navigation buttons for the menus.

At the right is a receptacle for the Crypto Ignition Key (CIK), which must be installed before the telephone can be used in secure mode. At the rear are the connections for the analogue PSTN line and for connection of the external power supply unit (PSU), which is not shown here.

Key storage device   К1634ДК4
At the centre of the right side of the device is a receptacle for a K1634DK4 (К1634ДК4) key storage device [3], the same one as used with the Russian M-427 message encryptor.

It is most likely an EEPROM device with a parallel interface, similar (but not identical) 1 to the KSD-64 from the US manufacturer Datakey, that was used with the American STU-III crypto phone.

 More about the KSD-64


  1. The number of contacts and the shape of the tip and the grip are different.

  • Type
    Crypto telephone
  • Pupose
    Speech and data traffic
  • Network
    Analogue PSTN
  • Serial port
    RS232C (asynchronous)
  • Intelligibility
  • Key storage
    K1634DK4 (Data Key)
  • Key length
    256 bits
  • Possible keys
  • Power
    110V/60Hz, 220V/50-60Hz
  • Consumption
  • Temperature
    5°C to 40°C
  • Dimensions
    290 x 280 x 130 mm (phone)
    238 x 110 x 100 (PSU)
  • Weight
    5500 g (phone)
    2800 g (PSU)
  1. BNTI, Secure speech and data terminal E-20
    7 December 2005. Retrieved 10 March 2022.

  2. BNTI, Secure speech and data terminal E-20M
    20 February 2007. Retrieved 10 March 2022.

  3. Roseltorg, Procurement for information carrier type DK-4
    13 April 2011. Retrieved 10 March 2022.
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Crypto Museum. Created: Thursday 10 March 2022. Last changed: Friday, 15 April 2022 - 06:59 CET.
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