Abstract
Structured p2p overlay networks have emerged as a dominant means for sharing and exchange of information on the Internet. However, they suffer from severe security threats, known as pollution attacks, in which malicious peers insert decoys in data object. The existence of such polluters is considered as a major problem since these systems are based on trust between peers to ensure the sharing and access to available resources. Pollution attacks ravages network resources and annoys peers with contaminated objects. Although there have been numerous works on pollution attacks, there have been no studies on these attacks in structured p2p overlay networks and all of them are not qualified to ensure security. This paper investigates the different strategies of polluter nodes and their impact on the security of communication. We also detail a monitoring process to supervise, detect and attenuate these threats. Our experiments show that our strategy decreases enormously the pollution attacks with a slight number of monitor peers.