Satellite-based tripartite measurement-device-independent quantum conference key agreement

Abstract Measurement-device-independent Quantum conference key agreement (MDI-QCKA) shares secure keys among multiple users by distributing postselected Greenberger-Horne-Zeilinger (GHZ) entanglement, improving practicality and security. Currently, the proposed QCKA protocols can achieve a communication distance of hundreds of kilometers over fiber link. However, such performance is only applicable to quantum communication within an inter-city range. To enable multi-user communication to cover a broader area, quantum satellites offer a solution. Here, one of the communication parties of MDI-QCKA is set as a satellite, and its performance is analyzed in combination with the characteristics of satellite-based link. Simulation results demonstrate the impact of the asymmetry of satellite-based and fiber link on system performance. In addition, considering the fluctuation of satellite-based link, the limitations on system performance caused by atmospheric turbulence, scattering particles, and pointing error are also simulated. These results provide a detailed analysis of the performance of satellite-based MDI-QCKA from the perspectives of satellite operation and the atmospheric environment, contributing to the expansion of MDI-QCKA to future global quantum communication networks.