An Efficient Key Management Scheme for Live Streaming

To protect multimedia content in live streaming applications, it is of critical importance to employ effective access control and key management schemes and to prevent unauthorized access. Many live streaming applications experience a large variation in the user number, high reconnection rate, and a large number of short sessions. Such frequent membership update may introduce significant rekey overhead and poses challenges to efficient key management. This paper considers applications that can tolerate a small amount of content leak, explores the unique characteristics of live broadcast streaming in membership dynamics, and investigates efficient key management mechanisms. Our proposed scheme uses the reconnection algorithm, batch rekeying and grouped user placement to reduce the communication and the computation cost associated with key update. Our analytical and simulation results show that the proposed scheme can reduce more than 50% of the rekey messages, and helps decrease the number of rekey messages that a user needs to decrypt by more than 90%.