| As an effective way to allocate resources or services,auction can bring huge economic benefits through competition.Electronic auction(e-auction)has gained an increasingly large market size in recent years because it has eliminated the physical limitation in traditional auction.However,due to the openness and anonymity of the Internet and people’s increasing attention to the protection of privacy,electronic auction is facing many new and distinctive challenges while promoting online transactions.In order to address issues such as low robustness,lack of trust with the auctioneer,and prevention of bids leakage,researchers have conducted a lot of research from the academic and industrial fields.Even though various solutions have been proposed,most of them cannot achieve decentralization(i.e.auctioneer-free),privacy-preserving(i.e.bids privacy),collusion-resistance,and secure-channel free simultaneously.In order to solve the above requirements,this thesis proposes an effective smart contract-based sealed-bid reverse auction scheme,namely SBRAC.Based on the decentralization,transparency,and record immutability characteristics of the blockchain,SBRAC scheme uses a well-designed smart contract to replace the common auctioneer role in auctions to achieve auction decentralization.By modifying the anonymous veto network,SBRAC scheme can provide robustness and bid privacy protection even when the vast majority of participants collude.In addition,SBRAC scheme combines the zero-knowledge proof and the anonymous veto network to reduce the demand of the auction on the communication channel.According to SBRAC scheme,all data is transmitted on a public channel and all operations are transparent in an auction.Through zero-knowledge proof,the proposed scheme is able to detect the presence of malicious manipulation,and all users can verify the auction process and results.This thesis also makes a detailed theoretical analysis of the proposed protocol.Security analysis is carried out from the aspects of correctness,privacy,fairness,confidentiality,non-repudiation,public verifiability and rule scalability.Complexity analysis shows that the SBRAC scheme has linear computation and communication complexity O(l)where l is the length of bids.It is independent of the number of bidders participating in the auction.Finally,this thesis builds a simulation environment,and further realizes the design of the prototype.Through a large number of experiments on the Ethereum test network,the auction time and gas cost are measured.The experimental results demonstrate that the SBRAC scheme has the high efficiency and practicality. |
