Abstract: With analyzing some unsafe factors of on-line electronic cash system such as the repeat attacks and reveal users’ information，this paper designs a RSA blind signature scheme，which creates a unique serial number by the Trusted Third Party TTP.Through discussion about safety and efficiency，this scheme has anti-repeat attacks，non-repudiation attack，anti-repeat draw and non-tracking，etc.even more security features.In addition，without adding timestamp and tracking electronic cash information，space efficiency has been improved only by storing the serial number.

Key words: RSA blind signature, electronic cash, Trusted Third Party（TTP）, serial number

摘要： 针对在线电子现金系统现有的重复攻击和用户信息泄露等不安全因素，设计了一种通过可信第三方加入序列号的RSA盲签名方案，并对方案的安全性及效率性进行了分析，该方案具有防重复攻击、防抵赖攻击、防重复支取、不可跟踪性等一系列安全性更高的特点，另外避免时间戳的加入，无需对电子现金信息进行跟踪、存储，只需存储所对应的序列号，大大提高了空间效率。

关键词: RSA盲签名方案, 电子现金, 可信任的第三方（TTP）, 序列号