Research On Multi-party Quantum Key Distribution

Quantum communication is a new research field combining quantum theory and information theory,which uses qubits as information carrier to carry out information interaction.With the increasing demand of communication,quantum communication has attracted more and more attention due to its advantages in information security,communication efficiency and communication capacity.This paper mainly studies the capacity and noise in multi-party quantum secret sharing protocol,as follows(1)In chapter 3,a scalable multi-party semi-quantum secret sharing scheme is proposed.Compared with existing schemes,the scheme can dynamically add or delete multiple user groups and users by using controlled non-gate(CNOT)and controlled Hadamard gate(CH),which improves the stability and flexibility of the scheme.In addition,the scheme involves only single qubit measurement that greatly weakens the hardware requirements of each user.(2)In chapter 4,a multi-party quantum key agreement based on high-dimensional Bell state is proposed.In this scheme,high-dimensional Bell state is adopted as the carrier of the encoding operation.There are two parameters of amplitude and phase in the high-dimensional unitary operation adopted in the scheme,and two-bit key information can be negotiated by one operation,which improves resource efficiency.(3)In chapter 5,during four kinds of common channel noises on quantum key distribution act on the channel problem,we have made a detail analysis on their influences.Finally,the range of the noise parameter X when the fidelity is greater than 0.9 is given.