A New Mechanism For Mutual Authentication In SIP

The greatest threat in the new generation network which is called NGN is unsafe authentication. Communication between new servers in NGN world is done based on Session Initiation Protocol (SIP). SIP is an application-layer control operating on top of a transport protocol which allows creating, modifying, and terminating sessions among more agents. For authentication, SIP relies on HTTP Digest by default; the client is authenticated to the SIP proxy server, called one way authentication, because in this approach we can authenticate client to server and the client can’t do any authentication in server side. In this paper we propose a mutual authentication mechanism that is not based on HTTP Digest and then, we implement our method in IMS and start to do authentication client to server is done in first step and server to client next. By this solution, we found that our proposed mechanism has more stability against intruder and unauthorized access to system. In this paper, we introduce a new approach for user authentication or server authentication by using OPTIONAL SIP’s header. In our solution we can increase necessary steps for intruder to decode authentication, compilation time and encoding time and save our system from some attack such as offline attack and replay