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Offline Transferable E-Cash Mechanism

E-commerce has developed rapidly in recent years and online transactions and digital services have become popular. However, existing trading systems such as ATMs, credit cards, Paypal, and prepaid systems are potentially unsecure and users' privacy is not sufficiently protected. To thus expand the applicability of e-cash systems, alternatives have become the goal of subsequent studies (e.g., offline transactions, transferability, and divisible e-cash). This study proposed an e-cash system with multiple denominations that enables e-merchants to give customers change when in an offline environment. The proposed system results in convenient transactions regardless of transaction amount and reduces the amount of e-cash users need to deposit in advance.