基于无证书群签名方案的电子现金系统

在经典方案ACJT群签名方案的基础上，提出了一种基于椭圆曲线的前向安全的成员可撤销无证书群签名方案，改进了ACJT计算复杂、参数较多、签名较长的不足，减小了计算量及参数个数，缩短了签名长度，提高了方案效率，并基于此群签名方案构建了一个离线公平高效的多银行电子现金系统，该电子现金系统不仅继承了群签名方案的安全性、高效性，还实现了不可伪造性、防止多重支付、防止金额篡改等多种性质，较同类方案具有明显优势。

Electronic cash system based on certificateless group signature

An efficient elliptic certificateless group signature with forward security and member revocation based on ACJT group signature was proposed. Compared to ACJT which has complex computation, many parameters and long signature length, proposed scheme has less parameters and only involve a small amount of computation. The length of proposed signature is short and the efficiency is high. A fair off-line multi-bank e-cash system based on this group signature scheme was also proposed. The new e-cash system has not only the high security and efficiency, but the unforgeability.It also can avoid dou-ble-spending and tampering money. The scheme has a clear advantage compared with others.