Technical Report TR-98-2, LCIS, Tamkang University, Taiwan, R.O.C., February 1998.

Abstract. An important type of electronic payment system is analyzed is this report. It is widely considered to have a variety of practical applications. Such kind of scheme handles a sequence of very small payments which therefore should be quite efficient to be payed and verified. A micro-payment scheme and its improved version proposed by Rivest is the best candidate for such applications. In general, there are three parties in the payment process: the payer, the receiver, and the bank. In this report, the Rivest's scheme is thoroughly studied and performance improvements for all the three parties are achieved.