Efficient Resource Registration and Location Scheme in P2P-SIP, using ID-based Signature

SIP (session initiation protocol) [1] is widely used in Internet as a signaling protocol for VoIP (voice over IP) and multimedia services. Recently, there have been some efforts to propose peer-to-peer SIP (P2P-SIP) architecture, which makes use of a peer-to-peer network instead of registrar and location SIP servers in order to facilitate SIP user registration and location. One of main issues in P2P-SIP is authentication of resource such as SIP user information without an authentication server. In order to authenticate the resources in P2P-SIP, the signature can be attached to the end of SIP message under PKI (Public Key Infrastructure) framework. However, the PKI-based signature model in P2P-SIP requires verification of central authorities (CA) during SIP message routing and certificates maintenance of intermediate nodes for authentication procedure. It causes much delay in signaling as users increase in P2P-SIP. Especially, much delay in signaling of real-time multimedia communication can be a significant problem. In this paper, we propose an efficient resource registration and location scheme in P2P-SIP, using ID-based signature which has more light-weight authentication procedures. ID-based cryptography is firstly proposed in [2], which is signature scheme, based on the bilinear pairings on elliptic curves. ID-based signature allows users to verify digital signatures using only public information such as the user's identity, while PKI-based signature requires verification of each user's public key from CAs. It can utilize public identifier such as e-mail ID or SIP-URI as a public key, so that it reduces the complexity and costs for establishing and managing the public key of nodes. In this paper, we identify efficiency of this resource registration and location scheme, using ID-based signature in comparison with PKI-based signature model through simulation.