电子拍卖的一个热点问题是保护标价的秘密性,因为存在第三方不可信任或相互勾结.提出了一个实用的保护标价安全的电子拍卖方案,除了中标价以外,它在任何勾结攻击情况下都能保证投标者标价的秘密性,可以公开验证中标价的正确性,效率远远高于最近Brandt提出的方案.其实现只需要O(log2υ)轮通信,其中υ是标价的范围.投标者注册使用数字签名后能保证协议的不可伪造性、抗重放攻击性和不可否认性.协议中使用零知识证明的安全性保证了系统的鲁棒性.
In most of the existing cryptographic auctions, the bidders' bids no longer remain confidential if the third parts collude. However, keeping the bids secret in any case is vital to the bidders because the bids are their true evaluations of the commodities and these evaluations may be their critical secrets. A Practical sealed electronic auction scheme of keeping bidders' bids confidential is proposed. No bid is revealed to anyone except the selling price even there exists serious collusion. Any one can verify that bidders follow the protocol to cast their bids and the winning price is correctly resolved according to opening rules. Also, the scheme is much more efficient than the recent publicly verifiable auctions by Brandt. In its typical implementation, the scheme requires at most O (log2 υ) rounds of communication, where υ is the range of bidding space. Non-forgery, replay-attack resistance and non-repudiation are achieved by the signature with temporary public key after registration by bidders. And the robustness of the system is based on the zero knowledge proof.