A Solution for Whitewashing in P2P Systems Based on Observation Preorder

We developed a model to investigate the phenomenon of whitewashing in peer-to-peer (P2P) systems. A white washer is a node that leaves the network and re-joins using a different identity. Whitewashing is a common problem in P2P systems and is a difficult to manage properly for reputable systems. The paper discusses the definition and properties of trust, formally represents the node by the labeled transition system. More specifically, our model uses observation preorder to identify white washers and to mitigate the effect of whitewashing.