Flexible Single Sign-On for SIP: Bridging the Identity Chasm

Identity federation is a key requirement for today´s distributed services. This technology allows managed sharing of users´ identity information between identity providers (IDP), and subsequently, the use of federated identities to access service providers (SP). Single sign-on (SSO) is a core feature provided by these systems. The Session Initiation Protocol (SIP) is a signaling framework for session call control. It is becoming a widely accepted layer for applications and services, especially in the telecommunications and multimedia domain. In this paper, we explore solutions to incorporate SSO process into the SIP framework in order to simplify the services and resources access. Our design leverages the liberty alliance specifications and extends the existing SIP standards to support SSO functionality. We also present a prototype implementation at the end of this paper.