Exploring the Feasibility of Reputation Systems under Churn

This letter examines how high rates of churn - the continuous process of node arrival and departure - affect rating mechanisms for peer-to-peer (P2P) networks. In particular, short peer lifetimes mean reputations are often generated from a small number of transactions, and thus are few reliable. To understand this relationship, this letter introduces an analytical model which determines the optimal transaction rate and the expected time to produce a reliable reputation, under both exponential and Pareto lifetime distributions.