Sustained Online Duration–based Reputation Management for File-Sharing Peer-to-Peer Systems

In open file-sharing P2P systems, there is generally no direct control or constraint on the participation of peers. Thus, Churn and Free-Riding become great challenges to these systems. This paper proposes a reputation management system based on sustained online duration (SOD-based system) to optimize the resources utilization in file-sharing P2P systems. In the SOD-based system, peers can enhance their reputation by increasing the duration of online time. Our scheme limits the number of times a peer provides services and introduces the bad rating records to prevent some malicious behaviors. The simulation and analysis show that SOD-based system increases the number of downloads, reduces Churn, and solves the problems of Cold-Start and Matthew Effect. Some malicious attacks, such as Sybil and Collusion, can not have bad effects on this system.