Performance evaluation of an authentication solution for IMS services access

The IP Multimedia Subsystem (IMS) is an access-independent, IP based, service control architecture. Users' authentication to the IMS takes place through the AKA (Authentication and Key Agreement) protocol, while Generic Bootstrapping Architecture (GBA) is used to authenticate users before accessing the multimedia services over HTTP. In this paper, we focus on the performance analysis of an IMS Service Authentication solution that we proposed and that employs the Identity Based Cryptography (IBC) to personalize each user access. We carry out the implementation of this solution on top of an emulated IMS architecture and evaluate its performance through different clients' access scenarios. Performance results indicate that increase in the number of clients does not influence the average processing time and the average consumed resources of the GBA entities during the authentication. We also notice that the Bootstrapping Server Function (BSF) presents a bottleneck during the service authentication which helps in giving some guidelines for the GBA entities deployment.