Source-Replacement Model for Phase-Matching Quantum Key Distribution

TL;DR

This paper reevaluates the security of the phase-matching quantum key distribution protocol using a novel source-replacement model, confirming its security and demonstrating its robustness against specific attacks.

Contribution

Introduces a source-replacement model for analyzing phase-matching QKD, providing a new perspective and deriving bounds on phase error rates under attack.

Findings

Security analysis aligns with original proof

Derived lower bounds on phase error rate

Demonstrated robustness against beam-splitting attack

Abstract

Quantum key distribution has emerged as a promising solution for constructing secure communication networks, offering information-theoretic security guaranteed by the principles of quantum mechanics. One of the most advanced quantum key distribution protocols to date is the phase-matching protocol. Its security was initially established using an abstract method known as symmetry-protected privacy. In this study, we reevaluate the security of the phase-matching protocol using an intuitive source-replacement model, and we arrive at conclusions that align with the original proof. This model provides a fresh perspective on the protocol's security. As an application of this approach, we introduce a beam-splitting attack scheme. Leveraging the source-replacement model, we derive a lower bound on the phase error rate under this attack, further underscoring the robustness of our security analysis method.