http://www.rfc-editor.org/rfc/rfc3711.txt
RFC 3711: The Secure Real-time Transport Protocol (SRTP), M. Baugher, D. McGrew, M. Naslund, E. Carrara, K. Norrman2004-03-01T23:00:00-00:00This document describes the Secure Real-time Transport Protocol (SRTP), a profile of the Real-time Transport Protocol (RTP), which can provide confidentiality, message authentication, and replay protection to the RTP traffic and to the control traffic for RTP, the Real-time Transport Control Protocol (RTCP). [STANDARDS-TRACK]