The performance of three-intensity decoy-state measurement-device-independent quantum key distribution

The performance of measurement-device-independent quantum key distribution (MDI-QKD) with three-intensity decoy-state is completely analyzed. The statistical fluctuation based on the central limit theorem is also considered both in symmetric and asymmetric cases. Our simulation results show that in the MDI-QKD system, the choice of the decoy state intensities is more important than the choice of the signal state. More significantly, the ratio between Alice's signal state optimal intensities and decoy state is well approximately equal to Bob's in the asymmetric case. These results can be used to optimize the practical quantum communication system.