Research On Quantum Private Comparision And Quantum Sealed-bid Auction

Secure multi-party computation (SMC) is a hot field in compute science. Its function is to complete the following computing task:in a multi-user network where no one trust each other, each user can cooperate to obtain the calculation result without revealing their private secret inputs. SMC has been studied extensively in the classic environment and its main applications are private bidding and auctions, voting by secret ballot, private comparison, private sort and so on. SMC has also wide application prospect in the military, political, financial, medical and so on.The technique of quantum information is a new cross discipline which is mutual integration of physics and information science. It applies the basic principle of quantum mechanics into computation, communication and cryptography of information science to form the three branches of quantum computation, quantum communication and quantum cryptography. Because of some of the specific nature of quantum mechanics, such as no cloning theorem, the uncertainty principle, and entanglement, quantum information technology have much better than the traditional information technology in computing speed, communication efficiency, security and so on. With the combination of quantum information technology and secure multi-party computation, there is a lastest hot research-----quantum secure multi-party computation. Due to the excellent properties of quantum information technology, the aspects of security, robustness, communication efficiency in the quantum secure multiparty computation protocols have been greatly improved than the ones in the secure multi-party computation protocols under the classic environment. Quantum secure multi-party computation have many research areas, such as: quantum private comparison, quantum auction, quantum voting, quantum sort etc..This paper has deeply studied two fields which are quantum private comparison and quantum auction in quantum secure multi-party computation. In order to improve the calculation efficiency, guarantee the security, reduce the implementation difficulty and simplify the operation, a plurality of protocols in these two fileds has been analyzed and researched. In the quantum private comparison:point out and improve the security vulnerabilities in quantum secure comparison protocol (QPC) which is based on the maximally entangled state (such as: GHZ state); propose a efficient and secure quantum secure comparison protocol which is based on asymmetric W states between two party; In quantum sealed-bid auction, propose a new quantum sealed-bid auction protocol (QSA), which adops the single particle state as information carrier and has a better efficiency compared with the existing quantum multiparty sealed-bid auction protocols (based on EPR state or GHZ state); utilize the quantum key distribution (QKD) technology and a hash function to improve the first quantum sealed-bid auction protocol based on EPR state. Specifically, the main work includes:(1) Analyze and improve the security vulnerabilities in a QPC protocol based on GHZ state in which a permutation operator is used to resist a special attack, namely the twice-Hadamard-CNOT attack, so that privacy and security of information can be guaranteed. Propose a new QPCE protocol which is based on asymmetric W states. More specifically, by using QKD, the third party (TP) cannot know the compared result and the security of information can be ensured.(2) Analyze the first quantum three-party sealed-bid auction which is based on EPR state, and by using the mature QKD technology and irreversible principle of Hash function, the security weaknesses in this protocol will be corrected. Utilizing single photons as information carrier, a new QSA protocol will be proposed, which has a better efficiency compared with the existing QSA protocols (based on EPR state or GHZ state). Then, deeply study that this new protocol how to be secure against various common attacks and why has a high efficiency.