A Micro-payment System for Multiple-Shopping

In this paper, we propose a micro-payment system that is able to apply to several vendors using only one hash chain. Explicitly, this scheme can be considered as an improvement and extension of PayWord [8] suggested by Rivest and Shamir in 1996. We focus on the scheme that guarantees atomicity and non-repudiation among requirements for payment systems. Atomicity and non-repudiation play an important role in payment systems. In particular, atomicity allows customers to use the payment system without loss of their money in any disaster. Finally, when a customer uses the micro-payment over several vendors,we analyze not only the efficiency in terms of the storage size but also the security issues.