Research On User Security Protocol Based On P2P-CDN VOD System

The rapid development of the Internet and the increasing availability of video content have led to a growing demand for IPTV systems.In the traditional C/S mode,server overloading becomes a system bottleneck,and the content distribution network(CDN)is less scalable,and needs to be complemented and integrated with P2 P technology.In addition,since P2 P networks are open and anonymous,there are certain security risks.Therefore,the security of P2 P networks is increasingly valued by researchers.How to improve the service quality of IPTV system,improve user experience and ensure system security in the case of minimal impact on the original CDN architecture is an important research content of this thesis.This thesis first proposes a new system architecture of P2 P and CDN fusion,and then designs the P2 P application layer private protocol for P2 P network based on IPTV system.Finally,a P2 P user trust model based on risk factor is proposed.The specific research contents are as follows:(1)Firstly,in order to improve the scalability of the existing CDN network of the IPTV system and improve the quality of service,a streaming media service system combining CDN and P2 P technologies is designed.The system integrates the P2 P network into the edge server of the CDN network,and establishes the P2 P autonomous domain to reduce the traffic load of the backbone network.On the basis of minimal modification of the original CDN architecture,the pressure on the server can be alleviated,and the stability of the system is ensured.(2)Secondly,in order to meet the requirements of data transmission in P2 P communication,a set of P2 P application layer private protocol for IPTV system is designed for the data transmission characteristics of IPTV.The protocol considers various factors such as control information,user information,video information,authentication information,file fragmentation type,etc.,can correctly encapsulate and parse video requests,and correctly return video content,so that nodes in the system can perform correct and efficient communication.The protocol ensures that the protocol implementation function is as small as possible,so that the number of control information bytes is occupied as much as possible,thereby reducing bandwidth occupation and improving user experience.(3)Finally,in order to protect the security of nodes in the P2 P system and resist the attacks of malicious nodes,a P2 P user trust model(RFTrust)based on risk factors is proposed.When calculating the local trust value,the model considers the collusion attack and the oscillating behavior,and introduces the risk factor.At the same time,the model considers the social attributes of the nodes,and introduces the recommended trust value.The global trust value of the node is weighted by the local trust value and the recommended trust value.The model uses incentive factors,penalty factors,etc.to control parameter changes and improve the model's resistance to attack and adaptability.