Hybrid Trusted Quantum Key Distribution Network Routing Scheme for Power Grid Environment

With the continuous development of quantum computing technology, Quantum Key Distribution (QKD) is an important means of secure communication in the post-quantum era. However, the high cost of trusted routing relays in QKD networks has hindered its widespread adoption in power systems. Reducing costs is the key to the popularization of QKD in large-scale data grid scenarios. Therefore, this paper proposes a routing scheme for QKD network in a hybrid trusted environment. Our scheme is based on SDN architecture, utilizing the characteristics of QKD network in hybrid trusted environment, through prioritizing the selection of trusted paths (composed entirely of trusted quantum nodes) and backup selection of hybrid trusted paths (composed of both trusted and semi-trusted quantum nodes), implementing a unified dynamic routing strategy to obtain the optimal quantum routing path. Furthermore, by collecting topology information and real-time link status of the power grid, a calculation method for the number of paths and link costs is proposed to maximize load balancing in the network. Finally, the simulation results demonstrate that our scheme outperforms routing schemes relying solely on trusted quantum nodes for key distribution, as well as other cooperative routing schemes involving semi-trusted quantum nodes, in terms of success rate of distribution and load balancing.