Quantum Key Distribution-Adaptation-Based Security Enhancement of Software-Defined Optical Network via Dynamic Quantum Resource Management

With the rising demand for secure and reliable telecommunication networks, efficient resource allocation strategies in quantum key distribution-based software-defined optical networks (SDONs) are becoming essential. In this research, we propose a heuristic adaptive quantum routing (RWTA_AQR) algorithm for routing, wavelength and timeslot assignment. RWTA_AQR utilises the FirstFit algorithm to assign wavelengths in both contiguous and noncontiguous timeslots for optimal resource utilisation based on the priority. To verify its effectiveness, the proposed RWTA_AQR is tested on NSFNET and UBN24 network topologies under diversified traffic models, towards low as well as high demand, network congestion scenarios. We use network security performance (NSP), success ratio of connection requests, timeslot utilisation, quantum key utilisation, blocking probability (BP) and security downgrade ratio as metrics to prove its effectiveness against the existing methods based on flexible security level, strict security level and classical approach. The results demonstrate that RWTA_AQR performs better by allowing NSP of up to 90% and having the lowest BP (below 10%) at lower traffic load. The proposed solution provides a systematic trade-off in security and resource utilisation with controlled overhead for improving the performance of QKD-SDONs in dynamic resource-constrained environments.