Research On Sealed-bid Electronic Auction Scheme Without The Third Party

The rapid development of electronic auction has brought great benefits to our lives, but its security problem is becoming more and more serious. In recent years, how to maintain the rights and interests of auctioneer and bidders has been attacted more attentions. The sealed-bid electronic auction has been better than other ways of electronic auction on the efficiency of bidding and protection of bidder privacy. Therefore, how to construct a secure sealed-bid electronic auction scheme is one hot research topic of many scholars.At present, the most schemes of sealed-bid electronic auction had existed a third party. However, the credibility of the third party is very difficult to be guaranteed. The sceure sealed-bid electronic auction scheme should not have the participation of the third party. In this thesis, we devoted ourself to construct the sealed-bid electronic auction without the third party; our purpose was to improve the security of the sealed-bid electronic auction system. Blind signature, ring signature, ring signcryption, homomorphic encryption and kinds of encryption technology have been very important applications in the privacy-preserving. These mentioned privacy-preserving technologies have been studied in this thesis, and they had been applied into the sealed-bid electronic auction system to ensure the relevant security requirements of the electronic auction system.The main works of this thesis are illustrated as following three aspects:1. Security analysis and improvement of two blind signature schemes without trusted PKG. Blind signature has invisibility for the message, and this invisibility of the blind signature can be used to ensure the confidentiality of the price in the sealed-bid electronic auction. In the research of blind signature, we analyzed the security of two blind signature schemes without trusted PKG, and found that they cannot resist the forgery attack against of the adversary AI, and gave the corresponding improved schemes.2. Sealed-bid electronic auction without third party scheme based on conditionally anonymous ring signcryption. Ring signcryption can achieve the confidentiality of the message and anonymity of the signer’s identity. The condition of anonymity of ring signature can ensure the non-repudiation of the signer. This thesis combined the ideas of the ring signcryption scheme proposed by Li with the conditionally anonymous ring signature scheme proposed by Zeng, and proposed a conditionally anonymous ring signcryption scheme. We applied the proposed conditionally anonymous ring signcryption scheme into the sealed-bid electronic auction system, and formed a sealed-bid electronic auction without third party scheme based on conditionally anonymous ring signcryption. The proposed scheme is fit for the government procurement, project bidding and other small-scale electronic auction.3. Sealed-bid electronic auction framework without third party based on homomorphic encryption. The sealed-bid electronic auction scheme without third party scheme based on conditionally anonymous ring signcryption is suitable for small scale situation. The homomorphic encryption technology can be convenient to find the corresponding results directly through the cipher text for large-scale encryption. This thesis analyzed the relevant problems of M.J.Li’s sealed-bid electronic auction scheme, and took advantage of homomorphic encryption and signature technology to construct a sealed-bid electronic auction framework without third party. The proposed framework was very suitable for large-scale electronic auction.