Enhancing key rates of QKD protocol by Coincidence Detection

TL;DR

This paper enhances practical quantum key distribution (QKD) by integrating coincidence detection with decoy pulses, improving key rates and security in real-world implementations through theoretical and experimental advancements.

Contribution

It introduces a novel combination of coincidence detection with decoy pulse methods and provides an easy algorithm for asymptotic key rate computation, supported by experimental validation.

Findings

Monitoring coincidences improves key rates in practical QKD.

The integrated protocol enhances security against vulnerabilities.

Experimental results confirm theoretical improvements.

Abstract

In theory, quantum key distribution (QKD) provides unconditional security; however, its practical implementations are susceptible to exploitable vulnerabilities. This investigation tackles the constraints in practical QKD implementations using weak coherent pulses. We improve on the conventional approach of using decoy pulses by integrating it with the coincidence detection (CD) protocol. Additionally, we introduce an easy-to-implement algorithm to compute asymptotic key rates for the protocol. Furthermore, we have carried out an experimental implementation of the protocol, where we demonstrate that monitoring coincidences in the decoy state protocol leads to enhanced key rates under realistic experimental conditions.