Multimedia Internet Rekeying for secure session mobility in ubiquitous mobile networks

Session mobility is one of new critical issues in the ubiquitous mobile networking environment. Session mobility provides a user changing its ongoing multimedia session, e.g., Voice-over-Internet Protocol (VoIP), from the currently using device to another by adapting user's demand. In session Initial Protocol (SIP)-based multimedia services supporting session mobility, SIP serves as a signaling control protocol to negotiate session control, whereas media is transmitted using Real-time Transport Protocol (RTP). For securing multimedia sessions, Multimedia Internet Keying (MIKEY) is embedded in SIP signaling to negotiate security parameters for Secure RTP (SRTP), whereas SRTP is used to protect media stream. Since session mobility allows an ongoing multimedia session to be transferred from one device to another, a new security problem is raised, i.e., sensitive parameters may remain in the previous device when the ongoing multimedia session has been transferred to the current device. Unfortunately, current MIKEY cannot bear the aforementioned security problem in session mobility. Therefore, we propose Multimedia Internet Rekeying (MIRKEY) for session mobility in the ubiquitous mobile networking environment. Although MIKEY can be executed again to carry out the rekeying of the session key and Crypto Session bundle (CSB) update, the sensitive parameters still remain in previous devices. MIRKEY contains a SBK to bind the participated user and multimedia session. Besides, SBK can persist in rekeying based on the key chain whenever a multimedia session is transferred to other devices. As a result, SBK is operative only in the specific device. As a result, MIRKEY can solve the newly raised security problem in session mobility. Furthermore, we verify MIRKEY using Burrows-Abadi-Needham (BAN) logic and realize it in the implemented ubiquitous multimedia service platform (UMSP).