Encryption in RTP

Definition

Encryption in Real-time Transport Protocol is used to ensure the confidentiality of the media content.

To transport multimedia over the Internet, appropriate protocol is needed. For instance, RTP, Real-time Transport Protocol [1], are created as a standard protocol for the end-to-end network transport of real-time data, including audio and video. Today, RTP is often used through Internet that can not be considered secure. To ensure the confidentiality of the media content, encryption has to be used. To support on-demand and live streaming media services, a streaming media system needs to support pre-encryption and live-encryption respectively. Further, the system must be capable of delivering the decryption key to the authorized clients securely.

In RTP, when encryption is desired, all the octets that will be encapsulated for transmission in a single lower-layer packet are encrypted as a unit. The presence of encryption and the use of the correct key are confirmed by the...