A Secure and Lightweight Micro-Payment Scheme in P2P Networks

In P2P networks, an economic measure is efficient to incentivize nodes to provide services to others. As the payment scheme is essential in the economic measure, an efficient and secure payment scheme is our goal. In this paper, we propose a mechanism that requires the nodes first purchase enough trivial scrip and then pay a piece of scrip for each service, such as a file piece (say 256KBytes) downloading. It's the payee who is responsible for the issue, signature, validation and double spending check of the scrip. Specially, the signature is generated only by one hash operation. Therefore, the mechanism not only guarantees security of the payment, but also is a lightweight scheme to implement. Besides, there are a quorum of trusted nodes to sign the peer's account information and several account holders to check the validity of the peer's account, thus the payment scheme is practical in the P2P networks despite of the characteristics of the peer's dynamic join and departure.