A Lightweight Secure SIP Model for End-to-End Communication

Session Initiation Protocol (SIP) is a signaling standard approved by IETF for real-time multimedia session establishment. Increasingly wide deployment brings much concern on SIP security. Current solutions for end-to-end signaling security either require user-side powerful performance support for heterogeneous security mechanisms, or assume that trust relationship is transitive and static. Yet no solution is suitable for weak terminals with inherent computational power limitations. It is necessary to consider a reasonable combination of security solutions could be provided by the end users and the network servers. This paper presents a hybrid security model, combining hop-by-hop and end-to-end security, that trusted neighbor servers help weak terminals to make end-to-end communication secure with lightweight overload. We believe it is also an engineering trade-off between capacity and security.