A Survey of Peer-to-peer Micropayment Schemes

P2P networks suffer from the free-riding problem, wherein users connect to the network only to use the resources, but do not donate any resources themselves. A popular approach to overcome this problem is to reward peers who share their resources, through payments. This has given a fresh lease of life to micropayments schemes, which are now being used in such networks. P2P Micropayment schemes need to address several requirements like transferability, anonymity, etc. that are not met by many traditional micropayment schemes. They must utilize the distinctive features of a P2P network to maintain high efficiency, while providing optimum security. In this paper we list out the requirements that need to be kept in mind while designing such schemes, present a survey of existing schemes, and analyze them critically. We also give a comparison of the schemes with respect to security and performance.