Caller identity privacy in SIP heterogeneous realms: A practical solution

The growing demand for voice services and multimedia delivery over the Internet has raised SIPpsilas popularity making it a subject of extensive research. SIP is an application layer control signaling protocol, whose main purpose is to create, modify and terminate multimedia sessions. Research has shown that SIP has a number of security issues that must be solved in order to increase its trustworthiness and supersede or coexist with PSTN. In this paper our purpose is to address such a weakness, namely the caller identity privacy issue. While some solutions to this problem do exist, we will show that they are inadequate in a number of situations. Furthermore, we will propose a novel scheme for the protection of callerpsilas identity which can also support roaming between different administrative domains. Finally, we provide some performance results, which demonstrate that the proposed solution is efficient even in low-end mobile devices.