- Secure telephone
A secure telephone is a
telephone that provides voice security in the form of end-to-endencryption for the telephone call, and in some cases also the mutualauthentication of the call parties, protecting them against aman in the middle attack.How secure telephones work
The practical availability of secure telephones is restricted by several factors; notably politics, export issues, incompatibility between different products (the devices on each side of the call have to talk the same protocol), and high (though recently decreasing) price of the devices.
Well known products
The best-known product on the US government market is the
STU-III family. However, this system has now been replaced by theSecure Terminal Equipment (STE) andSCIP standards which defines specifications for the design of equipment to secure both data and voice. The SCIP standard was developed by the NSA and the US DOD to derive moreinteroperability between secure communication equipment. A new family of standard secure phones has been created by Philip Zimmermann's based on the well recognized VoIP encryption standardZRTP based on an open standard.Privacy issues
The concerns about massive growth of
telephone tapping incidents lead to growing demand for secure telephones. Several companies offer their products, eg. Swiss [http://www.khamsa.ch PrivateGSM] , DutchCryptoPhone , GermanySecure Phone by securITus , SlovakSilentel SecureCall ,SecureGSM , AmericanRipcord Networks , or the secure telephone division ofSiemens AG .VOIP vs direct connection phones
As the popularity of
VoIP grows, secure telephony is becoming more of commonplace and less the lonely domain of spies andcivil libertarian s.Many major hardware and software providers offer it as a standard feature. What used to only be available at high expense and to a limited number of people is now freely available.
Other examples include the
Gizmo Project and Twinkle. Both of the former work with offerings from the founder of PGP, Phil Zimmermann, and his VoIP secure protocol,ZRTP .ZRTP is implemented inRipcord Networks product SecurePC with up to NSA Suite B compliant Elliptic Curve math libraries.ZRTP It's also being made available for mobile GSM CSD as a new standard for non-VoIP secure calls.There are several manufacturers of hardware Analog Telephony Adapters such as Sipura/linksys and Snom which offer easy to use [http://voxilla.com/tools/device-configuration-wizard/certificate-authority-service-for-linksys-analog-voip-adaptors-808.html secure] options.
Historically significant products
Products of historical significance are
PGPfone and Nautilus (designed as a non-backdoored alternative to Clipper), and now officially discontinued (but continuing living onSourceForge ) "SpeakFreely", and the security VoIP protocol wrapperZfone developed by the creator ofPGP .Other historical options involved scrambling generally using a form of
voice inversion . This was available from electronic hobbyist kit suppliers and is common on FRS radios.Analog scrambling products exist to this day because some telecommunications circuits, like HF links and telephone lines in the developing world -- are of very low quality.
See also
*
Mobile phone tracking
*ZRTP External links
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