Selfish Colluder Detection and Identification in Traitors within Traitors

During collusion attacks against multimedia forensics, an important issue that colluders need to address is the fairness of the attack, i.e., whether all colluders take the same risk of being detected. Although they might agree so, some selfish colluders may break away from their fair-collusion agreement and process their fingerprinted copies before collusion to further lower their risk. On the other hand, to protect their own interests, other attackers may wish to detect and prevent such selfish pre-collusion processing. It is important to study this problem of traitors within traitors, formulate the dynamics among colluders and build a complete model of multi-user collusion. This paper investigates techniques that attackers can use to detect and identify selfish colluders without revealing the secrecy of any fingerprinted copies. Our simulation results show that the proposed scheme accurately identifies all selfish colluders without falsely accusing any others.