Reliable numerical key rates for quantum key distribution

TL;DR

This paper introduces a reliable and efficient numerical method for calculating secure key rates in quantum key distribution protocols, enabling higher key rate estimations and facilitating automation and wider adoption in the field.

Contribution

The authors develop a new numerical approach that improves accuracy and efficiency in computing key rates for finite-dimensional QKD protocols, surpassing previous methods.

Findings

Higher key rates achieved for Trojan-horse attack scenarios

Improved key rate calculations for phase-coherent BB84 protocol

Enhanced potential for automating QKD security analysis

Abstract

In this work, we present a reliable, efficient, and tight numerical method for calculating key rates for finite-dimensional quantum key distribution (QKD) protocols. We illustrate our approach by finding higher key rates than those previously reported in the literature for several interesting scenarios (e.g., the Trojan-horse attack and the phase-coherent BB84 protocol). Our method will ultimately improve our ability to automate key rate calculations and, hence, to develop a user-friendly software package that could be used widely by QKD researchers.