Research On Anonymous Electronic Auction Protocol Based On Blockchain

In recent years,offline auctions have gradually turned to electronic auctions.Auctioneers usually post auction tasks with the help of a third-party,and users participate in bidding.However,the central third-party stores a large amount of sensitive data of user information,it is vulnerable to single-point attacks,which might lead to the leaking of critical information.Blockchain has the characteristics of decentralization,which can get rid of the problems brought by centralization.So a lot of researches have emerged in building secure electronic auction atop blockchain.However,these auction schemes were proposed in researches still have the following shortcomings:(1)user identity cannot be completely hidden during the auction process;(2)if the bidder violates auction rule and bids many times,his identity cannot be disclosed;(3)it lacks of control strategies over the rights to participate in auction;(4)the bidder needs to cost a large computing overhead.In order to solve above problems,this thesis researches on the anonymous auction atop blockchain,and we propose two auction schemes.Main works are as follows:(1)We propose a fair and anonymous auction scheme based on blockchain.In order to prevent the auctioneer from decrypting and revealing bid information in advance,we use two public keys of both the auctioneer and the Time Server to encrypt bid value.So we proposed a new way to guarantee the confidentiality of the bid and the fairness of the auction.By using blind signature technology and temporary address,we achieve the anonymity of bidding behaviors(the bidder identity is public,but others do not know his bid value).In this scheme,we can prevent malicious bidder from bidding multiple times.Moreover,the results of performance analysis show that users only cost less computational overhead.(2)We propose an anonymous auction scheme based on blockchain to support fine-grained control.We use attributes as elements of fine-grained control,and allowing only users with appropriate attributes(such as someone hold good reputation)to participate in auction.We realize the complete anonymity of the participant's identity through hiding the identity of the auctioneer and the bidder completely.We achieve the accountability through revealing the identity of malicious bidders and punishing them.We realize the confidentiality of bidding by encrypted the bidding value.At last,we conduct the security and performance analysis to verify the security and feasibility of this scheme.