Field test of quantum key distribution in the Tokyo QKD Network

TLDR

The network integrates six QKD systems into a mesh‑type topology, including a commercial product for long‑term stability and an interface to secure mobile phones. The network demonstrates secure metropolitan QKD, enabling world‑first 45 km TV conferencing, eavesdropper detection, secure path rerouting, and key relay via trusted nodes.

Abstract

A secure communication network with quantum key distribution in a metropolitan area is reported. Six different QKD systems are integrated into a mesh-type network. GHz-clocked QKD links enable us to demonstrate the world-first secure TV conferencing over a distance of 45km. The network includes a commercial QKD product for long-term stable operation, and application interface to secure mobile phones. Detection of an eavesdropper, rerouting into a secure path, and key relay via trusted nodes are demonstrated in this network.