A real-time QKD system based on FPGA

TL;DR

This paper presents a real-time Quantum Key Distribution system implemented on FPGA, achieving high-speed secure key generation over 20 km fiber with robust operation verified through continuous testing and encrypted voice communication.

Contribution

The paper introduces a novel FPGA-based real-time QKD system with integrated sifting, error correction, and privacy amplification for the first time.

Findings

Final key rate of 17 kbps at 20 MHz photon repetition frequency

Stable operation confirmed through 6-hour continuous testing

Successful encrypted voice communication demonstration

Abstract

A real-time Quantum Key Distribution System is developed in this paper. In the system, based on the feature of Field Programmable Gate Array (FPGA), secure key extraction control and algorithm have been optimally designed to perform sifting, error correction and privacy amplification altogether in real-time. In the QKD experiment information synchronization mechanism and high-speed classic data channel are designed to ensure the steady operation of the system. Decoy state and synchronous laser light source are used in the system, while the length of optical fiber between Alice and Bob is 20 km. With photons repetition frequency of 20 MHz, the final key rate could reach 17 kbps. Smooth and robust operation is verified with 6-hour continuous test and associated with encrypted voice communication test.