A unified trust management strategy for content sharing in Peer-to-Peer networks

Content sharing has emerged as a popular application in Peer-to-Peer (P2P) networks. The increasing number of free-riders and untrustworthy peers in content sharing network reduces the credibility of the shared contents. Also, the malicious peers pose the danger of security violation and bandwidth wastage by sharing polluted or infected contents in the network for their personal benefits. In this paper, we propose a unified trust management strategy by combining trust and security models with reputation based preferences for efficient content sharing in P2P networks. The problems in P2P content sharing, like free-riding, content pollution, content poisoning, peer availability, content availability, DoS attack, and flash crowd are considered in our unified trust management model. The model provides controlled scalability of the overlay network, and concurrently ensures the availability of contents for longer time in the network. The provider initiating content sharing is protected from Denial-of-Service (DoS) attack through restricted network size and interspersing the provider within a set of distributed peers. Performance measures, such as scalability, content availability, flash crowd and prevention of polluted or infected content distribution are compared with BitTorrent in heterogeneous environment. The advantage of this model is that it can be deployed easily in BitTorrent-like P2P networks. Simulation results show that controlled scalability helps in efficient utilization of bandwidth and protection for the providers, ultimately ensuring trust on the P2P network and the content shared. (C) 2012 Elsevier Inc. All rights reserved.