Information Security Mechanism Of Multi-party Participation In Quantum Network

Recently quantum information science has developed rapidly including quantum remote preparation(QRP),quantum teleportation(QT),quantum dense coding(QDC),quantum secret sharing(QSS)and quantum secure direct communication(QSDC)etc.However,due to imperfections of devices in the quantum communication system or the communication protocol,or the path failure,there are potential security risks in quantum communication system.Therefore,the study of the quantum information security mechanism is an important content of the quantum communication.In this regard,this paper studies the quantum key agreement,the design of redundant paths in the quantum communication network and joint remote preparation of quantum states in the security mechanism.Firstly,this paper proposes the implementation of multi-party secure quantum key agreement using five qubit Brown state.Based on the analysis of Brown state,we find that the Brown state has excellent entanglement properties.Combining the Brown state with the quantum key agreement,the protocol is divided into six simple steps,which ensures the security and efficiency of the protocol.Then this thesis gives a setting and working method of redundant paths in a quantum communication networks.In our method,the Bell state is used by default for the communication channel between two adjacent links.A signal needs to be transmitted in the work path and the protection path simultaneously to achieve the following signal protection mode.In the process of transmission,in order to improve the stability and reliability of the quantum communication network as the whole,the path switching of the main signal is completed at any time according to the working condition of the path.Because this research field is relatively novel,it fills the gap of quantum redundant path design in the quantum network.Finally,a joint remote preparation of arbitrary multi-dimensional equatorial quantum states is presented.By establishing a channel composed of two GHZ states products in advance,the preparation of the target state can be achieved by 100% with the help of two senders,and the joint preparation scheme of two particles can be successfully extended to the preparation scheme of multi-particle.