Research On Theory And Applications Of Secure Multi-party Quantum Computation

Secure multi-party computation(SMC) is an important part and hot field of modern cryptography, its main objective is to complete the following computing tasks:in a distrust distributed network, two or more participants wish to com-pute a specific function under the premise of the protection of their privacy data. SMC shows a big potential for the applications in the areas of data mining, sci-entific computation, electronic transactions, information retrieval, computational geometry, etc.Quantum information science is a newly emerged interdiscipline between in-formation science and physics, which applies quantum theory to areas such as communication, computation and cryptography, and thus forms three importan-t branches-quantum communication, quantum computing and quantum cryp-tography. Quantum information science outperforms its classical counterpart in communication efficiency, computing speed and security.The combination of quantum information science and SMC gives birth to a new research area-secure multi-party quantum computation(SMQC).Compared with classical SMC protocols, SMQC protocols achieve enhanced robustness, security and communication efficiency as a result of SMQC introducing excellent features of quantum information science, especially in eavesdropping detection, which is beyond the reach of the former.This thesis investigates theory and applications of secure multi-party quan-tum computation, supported by National Natural Science Foundation of China. The main contributions of this thesis can be concluded as follows:1. We have re-examined the limitations of secure two-party quantum computa-tion, and further demonstrated that there exists no unconditionally secure bit commitment and oblivious transfer in standard model by using Yao’s two-party computation model and combined with specified protocols.2. We have investigated the security of quantum secure function evaluation from two perspectives both generic protocols and primitive protocols, and pointed out the limitations of generic protocols in the secure two-party com-putation environment, and then proposed a practically secure two-party quantum scalar product scheme by introducing a non-colluding third party. The proposed scheme has a strong scalability, and can be used as a general solution of secure two-party function evaluation problems.3. Inspired from classical blind signature and multi-proxy signature models, we proposed a safe and efficient quantum multi-proxy blind signature scheme. Based on quantum entanglement and quantum entanglement swapping, the proposed scheme is easy to implement.4. We have investigated the security of quantum blind signatures from the per-spective of cryptanalysis. For WW09QBS protocol, we proposed an efficient attack scheme and further demonstrated that there exists a security flaw in the protocol—cannot satisfy the property of non-forgeability, and finally improved the origin protocol.5. We have investigated the security of quantum sealed-bid auctions from the perspective of cryptanalysis. For ZNZ10QA protocol, we proposed an effi-cient attack scheme and further demonstrated that there exists a security flaw in the protocol—a group of malicious bidders can collude to obtain other bidders’secret bids, and finally improved the origin protocol.