A Game Theoretical Approach in Securing P2P Storage against Whitewashers

An inherent problem to a cooperation incentive mechanism implemented into a dynamic system where peers may join or leave at any time is the whitewashing problem. Whitewashers are peers that repeatedly misbehave, leave the storage system and rejoin with new identities thus escaping punishment imposed by the incentive mechanism. In order to deal with such whitewashers, the paper presents a penalty mechanism against strangers and it describes as well a theoretical game that models such mechanism and attempts to capture the point of tradeoff between restricting whitewashers and encouraging newcomers to participate into the system.