Enabling Resilient Quantum-Secured Microgrids Through Software-Defined Networking

Quantum key distribution (QKD) has been considered a potent and mature approach to secure communication in the quantum era. However, there exist resilience gaps that hinder the practical usefulness of QKD. This article improves the resilience of a QKD-based microgrid by leveraging software-defined networking (SDN). Specifically, the following contributions have been made. First, a novel QKD- and SDN-based communication framework is devised for microgrids. Second, an enhanced QKD simulator is developed, which can simulate both the number of generated keys and the amount of classical data required, providing a more accurate QKD study in microgrids. Third, an SDN-based resilience enhancement strategy, which incorporates three practical SDN applications, is developed to improve the system's resilience. Finally, a QKD- and SDN-enabled cyberphysical microgrid prototype is built in an RTDS environment using real whitebox SDN switches. Extensive case studies validate the effectiveness and excellent performance of SDN to improve the resilience of QKD-based microgrids in various situations.