Trading in Trust, Tokens, and Stamps

Many peer-to-peer networks rely on cooperation between nodes. Reputation and payment protocols are two methods of introducing incentives to participate in systems such as Mojo Nation [10] and Free Haven [3]. We are interested in the relationship between reputation and payment protocols, in particular the types and properties of the economies and incentives they induce. Our work reveals some interesting parallels. It turns out that both types of protocol induce similar incentive schemes, in that there exists a more general protocol – stamp trading – which captures the essence of both. Our analysis and results have implications for many peerto-peer systems including spam-resistant networks, filesharing and routing.