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 ma-licious behaviors. Though free riders consume network bandwidth and decrease the network performance by displaying selfish behav-ior, 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 dis-rupt 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 mea-sures will eventually root out malicious peers from the system.