Feasibility Study of Sky-Underwater QKD Based on Asymmetric Channel

Aiming at the problem that the performance of existing sky-underwater quantum key distribution schemes is difficult to meet the relevant requirements in the environment of naval battle field, a sky-underwater quantum key distribution scheme based on phase matching protocol is proposed. In view of the channel asymmetry in the sky-underwater quantum key distribution scheme, an asymmetric phase matching protocol model is proposed to improve the classical phase matching protocol. The feasibility of sky-underwater quantum key distribution based on phase matching protocol under asymmetric channel conditions is studied by using correlation optimization method. The simulation results show that: Under dry and clean atmospheric conditions, in Jerlov I, II and III water bodies, the limit depth of underwater platforms is 1100m, 180m and 110m, respectively, based on the ability to generate keys. This performance basically meets the requirements of the current underwater platforms for concealability. At the same time, the distance between the air platform and the surface platform can exceed 100km, which has certain practicality. It has certain guiding significance for quantum network deployment.