PPay: micropayments for peer-to-peer systems

Emerging economic P2P applications share the common need for an efficient, secure payment mechanism. In this paper, we present PPay, a micropayment system that exploits unique characteristics of P2P systems to maximize efficiency while maintaining security properties. We show how the basic PPay protocol far outperforms existing micropayment schemes, while guaranteeing that all coin fraud is detectable, traceable and unprofitable. We also present and analyze several extensions to PPay that further improve efficiency.