A Reputation based System to Overcome Malicious Behavior in Peer-to-Peer Networks

In recent times, the growth in the number of subscribers of peer to peer networks has been phenomenal. Anonymity being a character of such networks also gave rise to the number of free-riders and malicious behaviors. Though free riders consume network bandwidth and decrease the network performance by displaying selfish behavior, they are not a serious threat for the rest of the co-operative peers. Malicious peers on the other hand, spread viruses, worms, Trojans in the network, provide misleading feedback and try to disrupt the existing trust among the peers. Therefore, it is absolutely essential that a peer has reliable reputation information about other peers in order make informed decisions (e.g., who to download files from, who to serve content, which is a malicious node etc.). In this paper, we have proposed a reputation system that uses objective criteria to track each peer’s contribution in the system and allows peers to store their reputations locally. In our opinion, such measures will eventually root out malicious peers from the system. 1