Soft actor-critic algorithm and improved GNN model in secure access control of disaggregated optical networks

To address the challenges of coordinated defense amid dynamic topology evolution and multidimensional security threats in decomposed optical networks, this study introduces the Graph-Entangled Security Actor-Critic (GESAC) model. GESAC is built on spatiotemporal modeling of evolving topologies and leverages a cross-layer spatiotemporal Graph Neural Network (GNN) to capture causal dependencies between optical path switching and access requests. Additionally, it enables adaptive delineation of security boundaries across multiple domains through federated representation learning. Within this framework, the Soft Actor-Critic (SAC) algorithm is employed to construct a policy optimization mechanism. By integrating entropy-guided multi-objective reinforcement learning, GESAC maps encoded network states to access control strategies, jointly optimizing for security, service quality, and system resilience. Experimental validation is conducted on a heterogeneous dataset comprising Cooperative Association for Internet Data Analysis (CAIDA) topology data, Canadian Institute for Cybersecurity Intrusion Detection Systems (CIC-IDS) access logs, and International Telecommunication Union Telecommunication Standardization Sector threat characteristics. The dataset encompasses 12 attack scenarios, 57,000 dynamic topology sequences, and 2.8 million cross-domain authentication events. Key findings include: (1) Threat Detection: GESAC achieves an F1-score of 0.915-0.931 in identifying physical-layer attacks such as wavelength eavesdropping and cross-domain privilege escalation, with a false positive rate as low as 0.7%. (2) Resource Optimization: Compared to greedy strategies, GESAC improves wavelength utilization variance by up to 58.9% and reduces end-to-end latency standard deviation by up to 57.7% under high-load conditions. (3) Policy Robustness: In scenarios involving topological mutations, the model increases Pareto frontier coverage by over 100% and reduces policy entropy decay rate by more than 65%, indicating strong robustness. (4) Scalability: At a scale of 100,000 network nodes, GESAC achieves a single-step decision latency of just 25.6µs and significantly reduces communication overhead, demonstrating excellent scalability. GESAC is designed to overcome the limitations of static security policies in the face of dynamic decomposition and large-scale attacks in optical networks. Integrating causal inference with game-theoretic equilibrium redefines the security control paradigm-shifting from passive defense to proactive resilience-and provides an interpretable, highly adaptive foundation for next-generation architectures such as multi-domain collaboration and computing-network convergence.