A Survey of SIP Authentication and Key Agreement Schemes

We present a survey of authentication and key agreement schemes that are proposed for the SIP protocol. SIP has become the center piece for most VoIP architectures. Performance and security of the authentication and key agreement schemes are two critical factors that affect the VoIP applications with large number of users. Therefore, we have identified, categorized and evaluated various SIP authentication and key agreement protocols according to their performance and security features. Although the performance is inversely proportional to the security features provided in general, we observed that there are successful schemes from both the performance and security viewpoint.