An enhancement of the SDP Security Description (SDES) for key protection

To provide VoIP traffic with message authentication and confidentiality, Secure Real Time Protocol (SRTP) and a media keying protocol are needed. SDP Security Description (SDES) is the most widely deployed keying protocol. It also needs Transport Layer Secure (TLS) over the VoIP signal protocol (SIP), known as SIPS. However, from several previous studies, SIPS can be compromised; then cause further problems on SRTP and SDES. So, in this paper, we propose a technique to enhance the SDES protocol to be secure even in the SIP environment without TLS.