Security for personal communications services: public-key vs. private key approaches

It is expected that personal communications services (PCSs) will provide access to the wireline telephone network for a large number of telephone calls via low-power, portable, digital radio telephones. The use of radio makes such a PCS more susceptible to eavesdropping than are conversations carried via wires. The mobility of PCS users also presents new problems relating to 1) authentication-ensuring service is not obtained fraudulently, and 2) the privacy of information about the PCS user´s location. It is important that PCSs provide privacy (of conversation and location) and fraud control comparable to that of the wireline network. The paper compares two approaches to providing privacy and authentication for PCSs: a conventional approach using “private-key” cryptographic technology, and a new approach using “public-key” technology. It is concluded that the public-key approach provides superior security while maintaining comparable call set-up performance