Efficient Routing for Quantum Key Distribution Networks

TL;DR

This paper models and compares routing protocols for large-scale quantum key distribution networks, analyzing how trusted nodes and repeaters affect performance and identifying key physical factors for future improvements.

Contribution

It introduces new routing protocols for quantum networks and evaluates their performance, providing insights into optimal node placement and device quality impacts.

Findings

Optimal placement of trusted nodes depends on device performance.

Routing protocol performance varies with network usage scenarios.

Physical device quality significantly influences secure communication rates.

Abstract

As quantum key distribution becomes increasingly practical, questions of how to effectively employ it in large-scale networks and over large distances becomes increasingly important. To that end, in this work, we model the performance of the E91 entanglement based QKD protocol when operating in a network consisting of both quantum repeaters and trusted nodes. We propose a number of routing protocols for this network and compare their performance under different usage scenarios. Through our modeling, we investigate optimal placement and number of trusted nodes versus repeaters depending on device performance (e.g., quality of the repeater's measurement devices). Along the way we discover interesting lessons determining what are the important physical aspects to improve for upcoming quantum networks in order to improve secure communication rates.