中文摘要：

在拍卖过程中如何保护投标者隐私和身份以及防止中标者反悔是设计安全电子拍卖系统的关键技术。基于环签名思想的类群签名方案及同态公钥加密体制，设计了一个新的密封投标的电子拍卖协议。所给协议具有如下特点：安全性好，能够满足投标者匿名、投标价保密、不可否认性以及不可伪造等密封电子拍卖的所有安全性要求；对可信赖第三方的依赖小；安全性高、步骤简略。

英文摘要：

Electronic auction is one of the basic businesses in electronic commerce. The protection of bidder anonymity and the prevention of bidder default are the keys in the designing of secure electronic auction scheme. This paper proposed fair electronic auction protocol, which was based on the combination of an efficient group signature scheme relying on the ring sig- nature idea and a public-key cryptosystem of the homomorphic encryption. This scheme has the following advantages： It has high quality of security and can satisfy all the secure requirements of sealed-bid auction, namely, bidder anonymity, bid undeniability, bid unforgeability, bid secrecy and bid confidentiality. It requires almost no participation of TTP. It is more efficient and safer than others.