Research On Measurement-device-independent Three-party Quantum Secure Direct Communication Based On Entanglement Swapping

Communication security is more significant in modern society.Quantum communication is a new and special way to achieve security communication.Its security depends on the principles of quantum mechanics,including Heisenberg uncertainty principle and no-cloning theory.Quantum communication includes Quantum Key Distribution(QKD),Quantum Secure Direct Communication(QSDC),Quantum Secret Sharing(QSS),etc.The QKD protocol provides random and secure keys between users,users encode and decode information by using raw keys which is transmitted by quantum channel.QSDC can transmit information directly in quantum channel without the need for pre distribution of keys,thus achieving the message they need.In experiments the two-step scheme of QSDC and the single photon DL04 protocol have been validated on fiber optic systems and quantum storage optical platforms,and a practical prototype of QSDC has been completed in 2020.In actual quantum communication systems,measurement devices have certain disadvantage,like security vulnerabilities which threaten the security of the actual quantum communication system.Therefore,researchers have introduced Measurement Device Independent technology(MDI)to compensate for this disadvantage.While in the current research,communication users are only peer-to peer network,we need more deep research on QSDC under the condition of multi-party,hence the main content is as follows:This paper proposes a QSDC protocol based on Entanglement Swapping(ES)to address the security vulnerabilities caused by actual measurement device disadvantages in practical QSDC and the problem of insufficient in depth research on multi-party QSDC.Combining the characteristics of QSDC,we proposed a three-party MDI-QSDC based on ES protocol.The main characteristics and advantages are that users perform corresponding encoding operations based on the information to be sent,use ES to establish an entanglement channel between users,and then hand over the measurement to a fourth party for publication of the measurement results.After this,users can obtain the transmitted information based on the measurement results of the fourth party.Compared to previous research,this protocol has the advantage of not only resisting all attacks from imperfect measurement devices,but also increasing the number of communication users,providing reference value for future multi-party quantum network communication.