A Trust-Based Robust and Efficient Searching Scheme for Peer-to-Peer Networks

Studies on the large scale peer-to-peer (P2P) network like Gnutella have shown the presence of large number of free riders. Moreover, the open and decentralized nature of P2P network is exploited by malicious users who distribute unauthentic or harmful contents. Despite the existence of a number of trust management schemes for combating against free riding and distribution of malicious files, these mechanisms are not scalable due to their high computational, communication and storage overhead. Moreover they do not consider the quality-of-service (QoS) of the search. This paper presents a trust management scheme for P2P networks that utilizes topology adaptation to minimize distribution of spurious files. It also reduces search time since most of the queries are resolved within the community of trustworthy peers. Simulation results demonstrate that the proposed scheme provides efficient searching to good peers while penalizing the malicious peers by increasing their search times as the network topology stabilizes. The mechanism is also found to be robust even in presence of a large percentage of malicious peers.