Unleashing Flexibility and Interoperability in QKD Networks: The Power of Softwarized Architectures

Softwarization and disaggregated architectures have transformed traditional communication networks by separating network control functions from the hardware, catalyzing innovation, and dramatically reducing deployment and operation costs. This paper extends these concepts to Quantum Key Distribution (QKD) networks, emphasizing the importance of virtualizing key management functions with advanced cloud-native technologies for enhanced global interoperability and flexibility. Our approach advocates for a fully disaggregated key management plane supported by softwarization and virtualization technologies, without losing sight of the established standards. The proposed model unlocks multiple benefits, including the facilitation of tailored access control mechanisms for QKD network administrators, the ability to apply real-time performance monitoring and base the control and management of the network on the gathered data, as well as conducting different key generation Quality of Service (QoS) admission control mechanisms on the QKD network. Moreover, a disaggregated model of the key management functions facilitates the implementation of different strategies for cross-domain collaboration between QKD network providers, as well as continuous key provisioning even in the midst of quantum infrastructure outages. The model has been validated through experiments in a virtualized environment, leveraging software tools to create customizable digital twins of QKD networks.