IP Multimedia subsystem authentication protocol in LTE-heterogeneous networks

Abstract

AbstractIP Multimedia Subsystem (IMS) introduces important advantages for users of LTE-femtocell heterogeneous access networks. In order to access services hosted in the IMS layer, the user has to undergo authentication procedure with the access network, followed by an authentication procedure with the IMS layer. This multi-pass authentication procedure is essential for securing IMS from malicious users, resulting in added overhead and possible quality of service degradations. The problem is further compounded when the user moves from one femtocell domain into another, which requires the authentication procedure to be repeated. To mitigate this problem, we present a lightweight, robust, and architecture-compatible IMS authentication protocol that implements a one-pass IMS procedure by promoting efficient key re-use for a mobile user. We make use of Home Node B femtocells to perform the role of IMS proxy. To verify the feasibility of using our protocol in mobile networks, an abstract model of our protocol is derived. The abstract model is emulated using Asterisk server and virtualization techniques. We also analyze the authentication delay of our proposed scheme. Numerical results reveal a reduction in user authentication delay of more than 50 percent compared to the existing authentication procedure.