可重复使用的匿名电子货币

Hitesh Tewari等人提出了一种利用秘密分割技术实现的可重用电子货币方案，但存在诸多不足，文中提出了一种新的基于杂凑函数的可重用电子货币万案，该方案模拟物理货币的重用过程。以权威授权的方式保障了用户对其货币的控制和重复使用时对货币所有权的移交，较好地实现了电子货币的可重用性，同时具有更高的安全性和可用性。

Reusable electronic cash with anonymity

Compared with physical cash, electronic cash processes many more advantages, but its reusability is paid less attention to. Developing reusable e-cash can not only improve efficiency and performance, but also enhance anonymity and untracability, thus processing more practical importance. Hitesh Tewari et al. proposed such a scheme using secret splitting, but with some disadvantages: (1) Anonymity gets compromised due to identity information in the scheme; (2) Cash will grow longer and longer along with their use, so there must be limitations on times; (3) Double spending won't be detected untill cash is deposited. In this paper, we propose a new scheme for reusable e-cash, which simulates the process of physical cash, and guarantees customers' control of their e-cash and handovers the ownership of e-cash when paying. Our scheme realizes the reusability in a perferable way, and has better secruity and usability.