Providing Secure Communication Services on the Public Telephone Network Infrastructures

摘要

The public telephone network has been evolving from manually switched wires carrying analog encoded voice of the 19th century to an automatically switched grid of copper-wired, fiber optical and radio linked portions carrying digitally encoded voice and other data. Simultaneously, as our security consciousness increases, so does our desire to keep our conversations private. Applied to the traffic traversing the globe on the public telephone network, privacy requires that our telephone companies provide us with a service whereby unintended third parties are unable to access other's data. However, existing public telephone network infrastructures do not provide such a service. This paper shows a method to enhance the PSTN call processing model to provide end-to-end voice privacy and access control services within the boundaries of the existing public telephone network infrastructures. Proposed enhancement uses public and symmetric key cryptography. This work is a part of an on going project on securing telecommunication system architectures and protocols.