Abstract: Forward security characteristic and strong blind characteristic are introduced simultaneously into E-cash system.Forward security characteristic can decrease efficiently the loss caused by key exposure.Strong blind characteristic can protect message sender or consumer’s right of privacy in practical application.The introduction of the two characteristics can improve extremely the security of E-cash system.The security of the scheme is based on the difficulty to solve discrete logarithm problem.

Key words: forward security characteristic, strong blind characteristic, E-cash, ElGamal

摘要： 首次将前向安全特性和强盲性同时引入到电子现金系统当中。前向安全特性能有效地减少因密钥泄露而带来的损失；强盲性在实际应用中起着保护消息发送方或消费者隐私权的重要作用。这两个性质的同时引入将在很大程度上提高电子现金系统的安全性，方案的安全性基于离散对数难解问题。

关键词: 前向安全特性, 强盲性, 电子现金, ElGamal