Collusion Detection and Prevention with FIRE+ Trust and Reputation Model

Recently many decentralized methods for trust management have been proposed. FIRE trust and reputation model presents a modular approach to trust and reputation from different information sources, according to availability, interaction trust, role-based trust, witness reputation, and certified reputation. However, FIRE model does not consider malicious activity and possible collusive behavior in the network nodes and is therefore susceptible to collusion attacks. In this paper we present a trust management approach to detecting collusion in direct and witness interactions among nodes based on history of interactions among nodes. Various interaction policies are defined to detect and prevent collaborative behavior in colluding nodes. Finally a multidimensional trust model FIRE+ is proposed for avoiding collusion attacks in direct and witness based interactions.