Abstract: Video-on-demand (VoD) based on Peer-to-Peer (P2P),as a new trend of the pay-IPTV service,has caused widespread concern in recent years.However,the instability and heterogeneity of the P2P network causing the existence of information security risks impede the realization of this system.On basis of conditional access mechanism of Video-on-demand system based on Peer-to-Peer network,we analyzed the insecurity factors of traditional system and proposed a kind of dynamic and two-way conditional access mechanism which is suitable for VoD system based on P2P.Mutual authentication protocol ensures the reliability of the identity of the communicating parties and generates the service key for transmitting control word,combing with the key agreement.This mechanism simplifies the design of system,and further improves the security of the system.

Key words: Peer-to-Peer,Video-on-demand,Conditional access,Mutual authentication,Key agreement