Switching Coordinator: An SDN Application for Flexible QKD-Networks

2026-03-14

AI Summary

This work addresses the limitations of traditional quantum key distribution (QKD) networks, which lack dynamic key resource scheduling and global optimization capabilities, rendering them vulnerable to link failures, critical-path assurance requirements, and supply-demand imbalances. The paper proposes the first software-defined monitoring and control framework tailored for switchable QKD networks. By leveraging software-defined networking (SDN), the framework enables real-time awareness of key generation, storage, and consumption states, and dynamically reconfigures network parameters through a global optimization strategy. This approach introduces SDN-based centralized control into switchable QKD networks for the first time, facilitating policy-driven key resource allocation and elastic management. It significantly enhances network performance and resilience by ensuring key availability for critical paths, improving fault recovery, and alleviating key generation bottlenecks.

Technology Category

• Planning, Routing, and Scheduling: Plan Execution and Monitoring
• Search and Optimization: Distributed Search
• Constraint Satisfaction and Optimization: Distributed CSP/Optimization

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Security and Privacy: Large-scale security measurements
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems

Abstract

A monitor and control framework for quantum-key-distribution (QKD) networks equipped with switching capabilities was developed. On the one hand, this framework provides real-time visibility into operational metrics. Specifically, it extracts essential data, such as the switching capabilities of QKD modules, the number of keys stored in buffer queues of the QKD links, and the respective key generation and consumption rates along these links. On the other hand, this framework allows software-defined networking (SDN) applications to operate on the collected information and address the cryptographic needs of the network. The SDN applications dynamically adapt the configuration of the switched network to align with its changing demands, e.g.,~prioritizing key availability on critical paths, responding to link failures, or reallocating generation capacity to prevent bottlenecks. This contribution demonstrates that the combination of switched QKD, centralized control, and global optimization strategies enables efficient, policy-driven operation of QKD networks. The cryptographic resources are allocated to maximize performance and resilience while remaining aligned with the specific policies set by network administrators.

Problem

• QKD networks
• switching capabilities
• cryptographic resource allocation
• dynamic configuration
• policy-driven operation

Innovation

• Software-Defined Networking (SDN)
• Quantum Key Distribution (QKD)
• Switched QKD Networks
• Centralized Control
• Dynamic Resource Allocation