New Novel Approaches for Securing VoIP Applications

SIP message authentication and SRTP key agreement are the important issue in the SIP-based VoIP service. Several secure solutions such as HTTP Digest Authentication, SSL/TLS, and S/MIME, are used for the SIP message authentication and key agreement. When the VoIP is used in the wireless environments, the efficiency of security service is one of the important matters in question. For the such efficiency, WPKI is a better substitution than the traditional PKI, while it still requires the effort on the certificate management. Therefore, we would like to propose efficient ID-based cryptosystem for the VoIP in the wireless environments. In this paper, we present the overview of WPKI and the application of ID-based cryptosystem for the SIP message authentication as well as the authenticated one-way key agreement for SRTP. Our novel design reduces delaying for the key generation and provides the explicit mutual authentication.