Simple and high-speed polarization-based QKD

TL;DR

This paper introduces a simplified, high-speed polarization-based quantum key distribution protocol using only three quantum states and a single laser, achieving state-of-the-art secret key rates over long distances.

Contribution

It proposes a novel, simplified BB84 protocol with fewer states and a single laser, enhancing security and speed in quantum key distribution.

Findings

Achieved secret bit rate of 23 bps over 200 km fiber

Repetition rate of 625 MHz

Reduced side-channel attack risks

Abstract

We present a simplified BB84 protocol with only three quantum states and one decoy-state level. We implement this scheme using the polarization degree of freedom at telecom wavelength. Only one pulsed laser is used in order to reduce possible side-channel attacks. The repetition rate of 625 MHz and the achieved secret bit rate of 23 bps over 200 km of standard fiber are the actual state of the art.