What Does Secure Real-Time Protocol Mean?
Secure Real-Time Protocol (Secure RTP or SRTP) is an extension of the RTP protocol with an enhanced security mechanism. It provides encryption, authentication and integrity verification of data and messages passed through the RTP-based communication protocol. Released in 2004, SRTP was developed by Cisco and Ericsson security experts.
Techopedia Explains Secure Real-Time Protocol
SRTP provides RTP protocol functionality while strengthening the security of unicast and multicast messaging, including multimedia messages and communication, like internet telephony and video conferencing. SRTP enforces an Advanced Encryption Standard (AES) algorithm to encrypt and decrypt all incoming and outgoing messages. The authentication mechanism provides a hash-based message authentication code (HMAC) algorithm, which implements a cryptographic hash function and secret key to validate a message's authenticity and integrity.
Secure RTP also protects against replay attacks by maintaining a message index, which is used to verify new messages.