Secure Real-Time Transport Protocol (SRTP) Library

The libSRTP library is an open source implementation of the Secure
Real-time Transport Protocol (SRTP) originally authored by Cisco
Systems, Inc.

SRTP is a security profile for RTP that adds confidentiality, message
authentication, and replay protection to that protocol. It is specified
in RFC 3711. More information about the SRTP protocol itself can be
found on the Secure RTP page.