Ad-hoc hybrid-heterogeneous metropolitan-range quantum key distribution network

TL;DR

This paper develops an adaptable metropolitan-range QKD network integrating fiber and free-space optical links, enabling rapid deployment and secure communication with cloud servers, overcoming limitations of traditional QKD systems.

Contribution

It introduces a versatile ad-hoc QKD network combining multiple physical channels and protocols, with strategies for rapid deployment and diverse topologies.

Findings

Successful implementation of a hybrid fiber and FSO QKD network

Rapid establishment of secure links using portable FSO terminals

Demonstration of quantum-secured connection to a cloud server

Abstract

This paper presents the development and implementation of a versatile ad-hoc metropolitan-range Quantum Key Distribution (QKD) network. The approach presented integrates various types of physical channels and QKD protocols, and a mix of trusted and untrusted nodes. Unlike conventional QKD networks that predominantly depend on either fiber-based or free-space optical (FSO) links, the testbed presented amalgamates FSO and fiber-based links, thereby overcoming some inherent limitations. Various network deployment strategies have been considered, including permanent infrastructure and provisional ad-hoc links to eradicate coverage gaps. Furthermore, the ability to rapidly establish a network using portable FSO terminals and to investigate diverse link topologies is demonstrated. The study also showcases the successful establishment of a quantum-secured link to a cloud server.