The Oracle - a New Intelligent Cooperative Strategy of Attacks on Trust and Reputation Systems

The paper presents a new concept of attack on trust and reputation systems. The oracle attack could violate the security provided by some of the existing reputation systems. The formal model of the attack is presented in the article on the base of the reference trust model, provided bythe author. The author has proved that this type of attack could be eficient. On the other hand,a sort of measures is provided in the paper which could be implemented in the reputation systems to overcome identified vulnerabilities, unfortunately at the cost of increase of system complication.The paper also provides a definition of intelligent strategies of attacks on trust and reputation systems based on cooperation of many malicious nodes and justifies why this type of attacks is a serious threat.