Asymmetric reference-frame-independent measurement-device-independent quantum key distribution

Abstract

Reference-frame-independent measurement-device-independent quantum key distribution is a promising candidate for building star-type quantum secure networks because it does not require reference alignment and removes all detector-side-channel attacks. However, prior works considered only a symmetric case in which the channels of both users have the same loss. In a realistic quantum secure network, the losses of various channels are likely to be different owing to their geographical locations. In this study, we present an asymmetric protocol for scalable reference-frame-independent measurement-device-independent quantum key distribution networks. By allowing independent adjustments of signal intensities of both users, our protocol provides a higher key rate than previous symmetric protocols in a realistic quantum secure network. The simulation results demonstrate that our protocol works well under realistic experimental conditions and obtains a key rate that is approximately one order of magnitude higher than that of previous methods. Our study paves the way for high-rate quantum secure communication network development.