Chip-based measurement-device-independent quantum key distribution

TL;DR

This paper demonstrates a secure quantum key distribution system over 200 km that eliminates measurement side-channels using integrated transmitters, enabling scalable and accessible quantum-secured communication networks.

Contribution

It introduces a chip-based measurement-device-independent quantum key distribution system that removes all measurement side-channels and uses mass-manufacturable integrated transmitters.

Findings

Secure key exchange achieved over 200 km.

Measurement side-channels effectively removed.

Cost-effective, scalable quantum communication platform.

Abstract

Modern communication strives towards provably secure systems which can be widely deployed. Quantum key distribution provides a methodology to verify the integrity and security of a key exchange based on physical laws. However, physical systems often fall short of theoretical models, meaning they can be compromised through uncharacterized side-channels. The complexity of detection means that the measurement system is a vulnerable target for an adversary. Here, we present secure key exchange up to 200 km while removing all side-channels from the measurement system. We use mass-manufacturable, monolithically integrated transmitters that represent an accessible, quantum-ready communication platform. This work demonstrates a network topology that allows secure equipment sharing which is accessible with a cost-effective transmitter, significantly reducing the barrier for widespread uptake of quantum-secured communication.