Secure Real-Time Transport Protocol

The Secure Real-Time Transport Protocol, as described in RFC 3711, The Secure Real-time Transport Protocol (SRTP), provides a framework for the encryption and authentication of Real-time Transport Protocol (RTP) and RTP Control Protocol (RTCP) streams. Both RTP and RTCP are defined by RFC 3550, RTP: A Transport Protocol for Real-Time Applications.

Encryption ensures that the call content and associated signaling remains private during transmission. Authentication ensures that (1) received packets are from the purported source, (2) packets are not been tampered with during transmission, and (3) a packet has not been replayed by a malicious server.