Experimental Quantum Key Distribution at 1.3 Gbit/s Secret-Key Rate over a 10-dB-Loss Channel

TL;DR

This paper demonstrates a floodlight quantum key distribution system achieving a record 1.3 Gbit/s secret-key rate over a 10-dB-loss channel, marking a significant step toward practical high-speed quantum-secure communication.

Contribution

First experimental demonstration of floodlight QKD reaching gigabit-per-second secret-key rates over metropolitan distances.

Findings

Achieved 1.3 Gbit/s SKR over a 10-dB-loss channel

First QKD to reach gigabit-per-second SKR

Advances practical high-rate quantum communication

Abstract

Quantum key distribution (QKD) enables unconditionally secure communication ensured by the laws of physics, opening a promising route to security infrastructure for the coming age of quantum computers. QKD's demonstrated secret-key rates (SKRs), however, fall far short of the gigabit-per-second rates of classical communication, hindering QKD's widespread deployment. QKD's low SKRs are largely due to existing single-photon-based protocols' vulnerability to channel loss. Floodlight QKD (FL-QKD) boosts SKR by transmitting many photons per encoding, while offering security against collective attacks. Here, we report an FL-QKD experiment operating at a 1.3 Gbit/s SKR over a 10-dB-loss channel. To the best of our knowledge, this is the first QKD demonstration that achieves a gigabit-per-second-class SKR, representing a critical advance toward high-rate QKD at metropolitan-area distances.