Single-photon measurement-device-independent quantum secure direct communication

Measurement-device-independent quantum secure direct communication (MDI-QSDC) protocol can prevent the divulgence of information caused by detector vulnerabilities. Existing MDI-QSDC protocol requires the utilization of entanglement sources which hinders the practical application of the protocol. In this paper, we propose a single-photon MDI-QSDC (SP-MDI-QSDC) protocol, which can realize secure communication using single-photon sources, thereby dispensing the entanglement preparation. In this SP-MDI-QSDC, quantum memory is used, and weak coherent pulses are used as the single-photon source. We conducted an analysis model for quantum memory and communication performance together with decoy-state techniques. The simulation results using actual experimental parameters show that our protocol has compelling communication performance, and the maximum secure communication distance can be further prolonged considerably by incorporating the technique of increasing capacity using masking (INCUM).