Gigahertz decoy quantum key distribution with 1 Mbit/s secure key rate

TL;DR

This paper demonstrates a gigahertz clocked decoy-protocol quantum key distribution system achieving record secure key rates of over 1 Mbit/s at 20 km, paving the way for practical, high-speed quantum communication.

Contribution

It introduces a high-speed QKD system using specialized self-differencing InGaAs detectors, achieving record key rates and enabling practical broadband quantum security.

Findings

Secure key rate of 1.02 Mbit/s at 20 km

Secure key rate of 10.1 kbit/s at 100 km

Use of compact non-cryogenic detectors

Abstract

We report the first gigahertz clocked decoy-protocol quantum key distribution (QKD). Record key rates have been achieved thanks to the use of self-differencing InGaAs avalanche photodiodes designed specifically for high speed single photon detection. The system is characterized with a secure key rate of 1.02 Mbit/s for a fiber distance of 20 km and 10.1 kbit/s for 100 km. As the present advance relies upon compact non-cryogenic detectors, it opens the door towards practical and low cost QKD systems to secure broadband communication in future.