An anonymous fair offline micropayment scheme

A micropayment scheme provides an efficient way for electronic payment with small face value. It is suitable for environments that require frequent transactions such as pay-per-view movie, video streaming, etc. Recent researches on micropayment introduce additional properties such as user anonymity and fairness in micropayments. However, existing schemes may lose efficiency while achieving the new properties. In this paper, we propose an anonymous micropayment scheme which achieves user anonymity and fairness at the same time. Besides, the broker's participation in the proposed scheme is offline. The user can make multiple payments with single withdrawal, and that is more efficient. Our scheme is a postpaid micropayment scheme which is more attractive to users compared with a prepaid one. To our knowledge, it is the first micropayment scheme meeting the above properties simultaneously.