Abstract
As a signaling protocol for controlling communication on the internet, establishing, maintaining, and terminating the sessions, the Session Initiation Protocol (SIP) is widely used in the world of multimedia communication. To ensure communication security, many authentication schemes for the SIP have been proposed. However, those schemes cannot ensure user privacy since they cannot provide user anonymity. To overcome weaknesses in those authentication schemes with anonymity for SIP, we propose an authentication scheme with anonymity using elliptic curve cryptograph. By a sophisticated analysis of the security of the proposed protocol, we show that the proposed scheme not only overcomes weaknesses in previous schemes but also is very efficient. Therefore, it is suitable for applications with higher security requirements.