A Survey of Security Issues in Trust and Reputation Systems for E-Commerce

Trust and reputation systems are always subject to attacks if an adversary can gain a benefit in doing so. The list of different attacks against them is extensive. Attacks like bad mouthing, newcomer, sybil, collusion and many more are subject to current research. Some of them present methods that allow to detect adversarial behaviour, hence providing protection against attacks. However, smart adversaries will adapt their behaviour strategies to the existing protection mechanisms and bypass some of the security methods. In this paper, we discuss the options available to adversaries for achieving their goal: Gaining a benefit. For this, we analyse the wellknown attacks and propose security methods which provide resistance or immunity against them at any time, hence independently from the cleverness or strategy of adversaries. Our second focus is to elaborate on the problem of reliably identifying an adversary amongst transacting participants and its influence on possible security methods.