Secure Voice Communication through Secure Telephone

The Secure Telephone is a communications system that meets the need for the protection of vital and sensitive information over a telephone system. Secure Telephone is a compact, self- contained, desktop unit capable of providing the user with both clear as well as secure voice and data transmissions. Its uniqueness lies in the fact that it works as an ordinary telephone simultaneously providing a secure telephone network to the other terminals. Secure Telephone is a telephone that provides voice security in the form of end-to-end encryption for the telephone call, and in some cases also the mutual authentication of the call parties, protecting them against a man in the middle attack.

The Secure Phone defeats telephone bugging and tapping attempts. Automatic telephone recording devices, line transmitters, or any other voltage-activated device will not function. The Secure telephone protects voice communications over PSTN, EPABX, VSAT TROPO, Hotlines, Leased Lines and ASCON networks.

Secure Telephone equipment may be used to provide secure communications on all commercial and military telephone networks.

Full feature Secure telephone terminals are equipped with modems that also allow clear and secure data transfer. However, some telephone networks do not provide the high-quality, low-noise circuits necessary for data transmission.

The Secure Telephone is operated in the same way as any regular telephone. Calls on Secure telephone are always initiated in a clear voice mode. Once the party you have called (at another secure telephone terminal) has answered, you have the option of talking to that person in the clear voice or secure voice mode.

Calls are always initiated in the clear voice mode, exactly the same as a normal telephone call. When two terminals communicate in the secure mode, each terminal automatically displays the authentication (identification) information of the distant terminal, and a list of compromised CIKs. This information is scrolled through the display window during secure call setup. The first line of the identification information and the classification level are displayed for the duration of the secure call. The information displayed indicates the approved classification level for the call, but does not authenticate the person using the terminal. The terminal users are responsible for viewing this information to identify the distant party

In this equipment three proprietary compression algorithms transform your voice into a digital stream corresponding to the achievable data rates (2 ' 400, 4 ' 800, 9 ' 600 bps). Voice-controlled half-duplex operation allows protected communications on channels, which do not support the full-duplex mode

The practical availability of secure telephones is restricted by several factors; notably politics, export issues, incompatibility between different products and high price of the devices. However, the Secure Terminal Equipment (STE) and SCIP (Secure Communications Interoperability Protocol) standards that defines specifications for the design of equipment to secure both data and voice have now replaced this system.

The concerns about massive growth of telephone tapping incidents lead to growing demand for secure telephones. Besides equipment, there are also software solutions available for secure VoIP. The most popular one is Skype, providing end-to-end encryption for PC-to-PC calls, though as it is closed-source, its security cannot be definitively verified.