Dynamic Routing for Quantum Key Distribution Networks

TL;DR

This paper introduces a dynamic routing strategy for quantum key distribution networks with trusted nodes and quantum repeaters, significantly enhancing key rates and network efficiency through adaptive decision-making and advanced post-processing techniques.

Contribution

It proposes a novel dynamic routing method tailored for near-future QKD networks, improving key generation efficiency and network performance over existing static approaches.

Findings

Dynamic routing improves key rates in asymmetric networks.

Post-processing techniques increase key rates in noisy environments.

Combining routing and post-processing yields further performance gains.

Abstract

In this paper, we consider quantum key distribution (QKD) in a quantum network with both quantum repeaters and a small number of trusted nodes. In contrast to current QKD networks with only trusted nodes and the true Quantum Internet with only quantum repeaters, such networks represent a middle ground, serving as near-future QKD networks. In this setting, QKD can be efficiently and practically deployed, while providing insights for the future true Quantum Internet. To significantly improve the key generation efficiency in such networks, we develop a new dynamic routing strategy that makes routing decisions based on the current network state, as well as evaluate various classical/quantum post-processing techniques. Using simulations, we show that our dynamic routing strategy can improve the key rate between two users significantly in settings with asymmetric trusted node placement. The post-processing techniques can also increase key rates in high noise scenarios. Furthermore, combining the dynamic routing strategy with the post-processing techniques can further improve the overall performance of the QKD network.