Predicting optimal parameters with random forest for quantum key distribution

Abstract

For practical quantum key distribution (QKD) in finite-data case, full optimized parameters can greatly improve its key rate. To gain such optimal parameters, traditional search algorithms are performed quite frequently despite the high time and hardware overhead, which may be a severe challenge for real-time QKD systems and large-scale QKD networks. In this paper, instead of searching optimal parameters, we employ random forest to directly predict those parameters. Firstly, we illustrate the feasibility of this method with 3-intensity measurement-device-independent QKD (MDI-QKD). Later, we rebuild a versatile model applicable to MDI and BB84 protocol simultaneously. Both numerical simulations demonstrate our method enjoys a low time and hardware overhead compared with traditional search method and achieves over 99% of the optimal secure key rate as well, which is very promising in future QKD applications.