A Bayesian Game of Whitewashing in Reputation Systems

作者：Seradji Shabnam; Fallah Mehran S^*

来源：Computer Journal, 2017, 60(8): 1223-1237.

DOI：10.1093/comjnl/bxx018

• ad hoc networks
• game theory
• peer-to-peer systems
• reputation systems
• whitewashing

Reputation systems have been proposed as a means to encourage cooperation among the nodes of a network. According to the reputation a node acquires on the basis of its behavior in the network, it may be allowed to receive, or may be deprived of, network services. However, due to free or low-cost pseudonyms and the reputation initially assigned to newcomers, reputation systems are vulnerable to the whitewashing attack, where a selfish node whitewashes its bad reputation by re-entering the network under a new identity. In this paper, we give a multistage game of incomplete information to model the interactions among the nodes of the network. Then, we find the minimal cost of getting a new pseudonym as well as the initial reputation assigned to newcomers so that nodes prefer cooperation to whitewashing as a perfect Bayesian equilibrium of the game. It is also investigated how the view of nodes toward the possible types of other nodes, reflecting how likely a node is selfish, may result in certain behaviors of the nodes.

• 出版日期2017-8