Agreement. The Srtp And Mikey Protocol Design And Implementation, In The Voip Terminal

With VoIP becoming popular, its security issue has being paid much attention to. From protocol's viewpoint, VoIP security problem includes two aspects, one of which is signaling security and the other is media security. This paper mainly discusses the issues of guaranteeing media security in VoIP.Built upon the project Designing VoIP Terminal Based on Coldfire Platform, My task is designing two protocol modules: the Secure Real-time Transport Protocol (SRTP) and Multimedia Internet KEYing (MIKEY), and then implements them on target platform. SRTP uses efficient AES algorithm to guarantee confidentiality of RTP payload, and uses HMAC-SHA1 algorithm to provide data integrity as well as to prevent hostile replay hacking. MIKEY is responsible for negotiating parameters of SRTP protocol and generating and transporting various keys used by SRTP.Coldfire MCF5235 MCU has a hardware security unit, which can implement popular encryption algorithms and digest algorithms. These security algorithms in SRTP/MIKEY can be implemented by the security unit, so this paper also presents how to use it to implement these algorithms.Based on Ericsson SRTP/MIKEY library and the project's characterizes, the design of both modules has been finished; the implementation section introduces how to port these protocols to eCos operating system and illustrates it using code walk through. After that I integrate both modules into VoIP protocol stack, including SRTP module's integration into RTP module and MIKEY module's integration into SIP module.At the end, the paper provides test methods and result analysis of SRTP and MIKEY protocols. Firstly, these modules were tested about function correctness and the test result indicates both protocols can achieve their function defined in their specifications; then compatibility tests were executed and the result shows that the implementation does well in compatibility with other implementation. Finally I finished the performance test and the test result indicates that our implementation accords with corresponding requirements in VoIP system.