According to statistics, most P2P applications use Gnutella or BitTorrent protocols to combat free riders. However, BitTorrent restrains free riders using the choking algorithm that chokes free riders only. Whereas, Gnutella identifies and prevents malicious nodes using the EigenTrust algorithm that has been proven to be imperfect. Therefore, both of these schemes are inefficient. According to a research conducted in 2005, 85% of Gnutella network users are free riders and only 1% of the users share new files and resources voluntarily. In this paper, by considering users' bandwidth, computing power and energy, our proposed system architecture gives users corresponding counters, which are stored and managed by the server. Moreover, the file-sharing model of our system can be divided into real-time streaming media sharing and file sharing. As for real-time streaming media sharing, users can use their counters to participate in the auction and bid on the admission of high-quality real-time streaming. As for file sharing, users have to pay a certain number of counters for every unit of download bandwidth. That is to say that all system users must use the counters to bid on or purchase services, which further enables users' spontaneous resource sharing.
Journal of Network and Computer Applications 41, pp.47–55