Quantum Proxy Blind Signature And Its Application

The emergence and rapid popularization of internet and computer make human beings enter the information era,and information has become a new resource.With the development of information technology,information security has become a social demand,and the guarantee of information security has become the focus of global attention.Information security is related to not only the quality of personal digital survival and social stability,but also the national economy and politics.As an important part of cryptography,digital signature plays an important role in protecting information security.However,with the research of quantum mechanics,the coinmunication security mechanism based on classical digital signature is threatened.So some scholars applied quantum mechanics to digital signature,resulting in quantum signature technology.Compared with classical signature,quantum signature technology not only meets the unforgeahility,blind property and undeniability,but also provides unconditional security.We research quantum signature and its application.Based on the characteristics of proxy signature and blind signature,this thesis proposes the following two schemes:quantum proxy blind signature and third-party e-payment protocol.The research results are as follows:1.We present a proxy blind signature protocol based on controlled quantum teleportation.In the protocol,we utilize physical characteristics of quantum mechanics to implement signature,delegation and verification and five-qubit entangled state functions as channel.In order to ensure the safety,quantum key distribution protocol and one-time pad are adopted.Compared with some signature schemes,the scheme can complete the whole signature process by using five-qubit entangled state,which not only has unconditional security,but also reduces measurement times.2.In this thesis,wo take four-qubit,entangled state as communication resource and propose a trusted third-party e-payment scheme which is based on quantum proxy blind signature.Its verifiability is guaranteed by using single particle unitary operation and quantum measurement.In this scheme,a single-particle state can be carried two-bit classical messages,which can save a lot of resources.Furthermore,if there is a dispute among internal participants,it can be solved with the assistance of the third-party e-payment,platform.