Design And Analysis On Semi-quantum Key Agreement Protocols

With the continuous development of quantum computing,classical cryptosystems that rely on mathematical difficulties and computational complexity to guarantee security are constantly under threat.Therefore,in recent years,the emerging discipline formed by the combination of quantum mechanics and cryptography,namely quantum cryptography,has attracted the exploration interest of a large number of researchers.At present,quantum cryptography has been developed into several research fields,such as quantum key distribution and quantum key agreement.In addition,the research interests of scholars are also attracted by the fields of quantum secret sharing,quantum secure direct communication,quantum authentication and quantum secret comparison.Among them,quantum key agreement protocol is an important part of quantum cryptography research and has important application value.In real life,quantum key agreement is widely used in scenarios such as end-to-end communication and the Internet of Things.Although the current quantum key agreement protocol has been able to establish a secure and reliable shared secret between all legitimate participants,the participants of the current protocol are required to have high capabilities and equipment.To overcome this difficulty,a semi-quantum key agreement protocol has been proposed by experts.One or more participants in a protocol are allowed to have only a single quantum capability,so the capabilities and device requirements of the participants in such a protocol are reduced.Currently,the proposed secure semi-quantum key agreement protocols have some deficiencies in terms of protocol performance and there are quantum resources wasted.Moreover,multi-party semi-quantum key agreement protocols require the assistance of a trusted third party to be implemented.In this thesis,improvements are made to address these issues.The purpose of this thesis is to design two semi-quantum key agreement protocols,which are based on the G-like states and the four-particle Cluster states,respectively,and analyze them in depth to prove that they have good performance.The main research contents of this paper are as follows:1 By exploiting the special entanglement of G-like states,a two-party semi-quantum key negotiation protocol is designed.In this protocol shared keys can be established fairly by two semi-quantum parties with the assistance of a trusted third party with full quantum capabilities.Since two semi-quantum parties are allowed to perform only simple quantum state preparation and measurement.Therefore,the requirements for participant capabilities and equipment are largely reduced.In its ultimate analysis,the protocol proved to be stable against participant attacks and external attacks.Furthermore,the protocol proved to be superior in terms of performance.2 A four-party semi-quantum key negotiation protocol is designed by exploiting the entanglement of four-particle Cluster states.It ensures that shared keys can be established fairly by three semi-quantum participants with the assistance of one participant with full quantum capabilities.Furthermore,the requirements for participant capabilities and equipment are not only reduced in this protocol,but also no trusted third-party involvement is required.Ultimately,the analysis shows that participant attacks and all external attacks can be effectively defended against by the protocol.Moreover,the protocol has excellent performance.