sStream: Peer-to-Peer Live Streaming with Efficient User Authentication and Key Management

Recent development of peer-to-peer (P2P) based media streaming technique brings unprecedented new momentum to the Internet streaming, which has been shown to be cost effective, scalable and easy to deploy. However, before these applications can be successfully and commercially deployed, it is very significant to achieve efficient access control mechanisms. Based our earlier research of secure streaming architecture of TrustStream, this work continues in-depth study on how to ensure that only the authorized users can access the correct media in p2p live streaming systems by adopting proposed user authentication and key management schemes. The main properties of presented secure systems include: i) the management server issues each authorized user a unique public- key certificate for other participant verifying its legal identity; ii) the lifetime of issued certificate is based upon media content instead of host\´s system time; iii) one-way hash-chain technique is employed to extend the certificate\´s lifetime; iv) the media is encrypted by the session key (SK) and then delivered to the communication group members; v) the SK is updated periodically and irrespective of clients\´ behaviors; vi) the re- keying messages are selectively distributed to legitimate users via the p2p overlay network. Moreover, the analysis shows the efficiency, scalability and robustness of given schemes in p2p live streaming systems, named "sStream".