Research on the Application of Four Dimensional MDI-QKD Protocol Based on Phase Polarization Coding in Quantum Communication Systems

Based on the analysis of the security performance and existing problems of quantum key distribution (QKD) protocol and measurement device independent quantum key distribution protocol (MDI-QKD), this article proposes a four-dimensional MDI-QKD scheme based on phase polarization hybrid encoding, combining phase polarization encoding, quantum state fusion and segmentation principles, and high-dimensional MDI-QKD scheme, and designs a matching four-dimensional simulation model. The simulation results show that under different polarization dismatch parameters, the performance of the four-dimensional MDI-QKD scheme based on hybrid encoding has been significantly improved in terms of key generation rate and secure communication distance.