Colluding clique has become the first threat to trust model. However
today’s trust models in P2P network are known as green hand in handling colluding cliques. CCD
a colluding clique detector
was proposed to detect the exis-tence of colluding clique by measuring similarity of peer’s activities
which included a mathematical description and a distributed implementation. The simulation results show that CCD is considerably effective in detecting colluding cliques and trust model with CCD is more reliable and has higher success rate than the same trust model but without CCD espe-cially when many colluding cliques exist.