Progress in satellite quantum key distribution

TL;DR

Satellite-based quantum key distribution extends secure communication range beyond ground limitations by leveraging space links, with ongoing research addressing protocols, infrastructure, and technical challenges for global deployment.

Contribution

This paper summarizes recent progress, protocols, and technical challenges in developing satellite quantum key distribution systems for global secure communication.

Findings

Satellite QKD can overcome ground-based distance limitations.

Multiple international initiatives are actively developing satellite QKD.

Technical challenges include link quality and infrastructure development.

Abstract

Quantum key distribution (QKD) is a family of protocols for growing a private encryption key between two parties. Despite much progress, all ground-based QKD approaches have a distance limit due to atmospheric losses or in-fibre attenuation. These limitations make purely ground-based systems impractical for a global distribution network. However, the range of communication may be extended by employing satellites equipped with high-quality optical links. This manuscript summarizes research and development which is beginning to enable QKD with satellites. It includes a discussion of protocols, infrastructure, and the technical challenges involved with implementing such systems, as well as a top level summary of on-going satellite QKD initiatives around the world.