Secure Real-time Transport Protocol

The Secure Real-time Transport Protocol (SRTP) is a profile for Real-time Transport Protocol (RTP) intended to provide encryption, message authentication and integrity, and replay attack protection to the RTP data in both unicast and multicast applications.

It was developed by a small team of Internet Protocol and cryptographic experts from Cisco and Ericsson.

SRTP and SRTCP use Advanced Encryption Standard (AES) as the default cipher.

Hence the SRTP standard also provides the means to secure the integrity of data and safety from replay.

This approach relies on the integrity protection to make it impossible to modify the sequence number without detection.

This provides protection against certain attacks which are easier to carry out when a large amount of ciphertext is available.