High-Fidelity Coherent-One-Way QKD Simulation Framework for 6G Networks: Bridging Theory and Reality

TL;DR

The paper addresses the need for practical design tools in QKD by introducing an experimental‑verified COW‑QKD simulation framework aligned with ETSI interfaces and validated against real dark‑fiber deployments. It combines a physics‑informed model of COW protocols with an ETSI‑compliant API and a modular KMS, verified through a dual‑node experiment using Clavis3 hardware. Results show close alignment between simulations and measurements across multiple distances and configurations, supporting the framework’s use for pre‑deployment analysis and design guidance. This work meaningfully bridges theory and practice, enabling safer, more scalable integration of QKD into next‑generation networks.

Abstract

Quantum key distribution (QKD) has been emerged as a promising solution for guaranteeing information-theoretic security. Inspired by this, a great amount of research effort has been recently put on designing and testing QKD systems as well as articulating preliminary application scenarios. However, due to the considerable high-cost of QKD equipment, a lack of QKD communication system design tools, wide deployment of such systems and networks is challenging. Motivated by this, this paper introduces a QKD communication system design tool. First we articulate key operation elements of the QKD, and explain the feasibility and applicability of coherent-one-way (COW) QKD solutions. Next, we focus on documenting the corresponding simulation framework as well as defining the key performance metrics, i.e., quantum bit error rate (QBER), and secrecy key rate. To verify the accuracy of the simulation framework, we design and deploy a real-world QKD setup. We perform extensive experiments for three deployments of diverse transmission distance in the presence or absence of a QKD eavesdropper. The results reveal an acceptable match between simulations and experiments rendering the simulation framework a suitable tool for QKD communication system design.

Figures (10)

• Figure 1: High-level QKD framework.
• Figure 2: QKD Applications architecture.
• Figure 3: QKD fibre link and QKD equipment.
• Figure 4: QBER of a) COW3 and b) COW4.
• Figure 5: Keyrate of a) COW3 and b) COW4.