匿名功能是保護消費者的個人交易資訊隱私的必要功能；後付款的方式對消費者較為便利，因為消費者可以享受先購買商品後付款的便利。Huang在2006年提出了後付款的匿名小額付款方法。但Huang的方法倚賴一個公正的中央銀行，它同時提供消費者的匿名性以及銀行的金融服務，但是建立與維護一個公正與安全的中央銀行，是一件困難且工程浩大的工作，因此Huang的方法在實現上有其困難。為了移除中央銀行這個角色，我們提出了一個具有匿名撤銷的後付款匿名小額付款方法。本研究不僅解決了Huang的方法的缺失，與Huang的方法相比較，並且提供較有效率與較可行的方法。不僅如此，本研究為首篇利用同時簽章法來提供消費者匿名的小額付款方法。 Anonymity is a necessary property for postpaid micropayment schemes to protect the customers’ privacy. The customers also gain the shopping convenience in postpaid way. In 2006, Huang first proposed an anonymous postpaid micropayment scheme that needs a trusted bank to provide customers’ anonymity and finance services. However, the building and maintenance of trusted banks causes the impracticality of Huang’s scheme. To remove trusted banks, a postpaid micropayment scheme with revocable customers’ anonymity is proposed. Our scheme not only overcomes the impractical frauds in Huang’s scheme but also is more efficient and practical than Huang’s scheme. Moreover, our scheme is the first micropayment scheme adopting concurrent signature schemes to provide customer anonymity.
