Operation of uncrewed maritime vehicles in remote over-the-horizon environments depends heavily on satellite communication as their primary command and control (C2) link with other remote offshore assets and shore-based operators. As the maritime sector moves toward greater autonomy, protecting these communication channels becomes a critical priority for global trade and safety. However, satellite propagation delays and signal intermittency may cause standard authentication protocols to exceed timeout thresholds, disrupting real-time policy enforcement. Current security frameworks, such as those developed by the National Institute of Standards and Technology (NIST) and International Maritime Organisation (IMO), while necessary, are insufficient to address these challenges as they assume stable, low-latency connections and continuous human oversight.

This research develops a zero-trust framework for maritime satellite communication. The architecture uses an asset registry compliant with the Australian Maritime Safety Authority regulatory requirements. It integrates continuous device verification, short-lived certificates, and adaptive policy evaluation. Despite constrained telemetry, a hybrid anomaly-detection ensemble, trained on real network data, is used to identify cyber threats. To secure the onboard network, the framework enforces a ship-system-aware segmentation model and implements Virtual Local Area Network (VLAN) and Software-Defined Networking (SDN) micro-segmentation to achieve progressive isolation. A cryptographic recovery pipeline maintains security during degraded satellite links. A hybrid cyber-physical co-simulation, pairing real network traffic with simulated autonomous maritime dynamics, validates the framework’s performance.

This framework provides four primary outcomes. First, the hybrid ensemble provides broader threat coverage than single detection models by compensating for individual limitations. Second, progressive isolation is essential; full disconnection causes operational failures as severe as the cyber-attack itself. Graduated responses preserve mission-critical resilience during threat containment. Third, the connectivity-aware recovery mechanism addresses the fundamental requirement for uncrewed maritime vehicles by operating without continuous satellite communication. Fourth, the co-simulation demonstrates that network isolation forces the vehicle’s autonomy stack to prioritise safety during satellite link loss. While protective, this transition increases cross-track error and reduces mission completion, proving that evaluating maritime cyber resilience requires measuring mission-critical impacts rather than detection metrics alone. Consequently, autonomous maritime security frameworks must prioritise progressive isolation, treat mission continuity as a core design input, and account for satellite communication degradation in recovery protocols.

Adapting zero-trust principles to constrained maritime settings establishes cyber resilience as a fundamental requirement for satellite communication. This approach secures satellite links to mitigate mission failure and prevent the loss of critical assets during targeted cyber-attacks. By addressing the inherent vulnerabilities of these communication channels, the framework ensures that remote missions remain unhindered and predictable.

• Adaptation of zero-trust for maritime constraints: This work shows that standard security frameworks cannot adequately address the high latency, intermittent satellite connectivity typical of maritime environments. A zero-trust framework tailored to these conditions is required - one that continuously verifies integrity, authenticity, and operational status of all onboard and shoreside component through a maritime-specific asset registry.
• Progressive isolation for operational continuity: Full system disconnection during an attack often causes as much operational harm as the breach itself. Graduated network responses allow for threat containment while maintaining mission-critical functions.
• Requirement for connectivity-aware recovery protocols: Recovery protocols must account for degraded communication states. This framework ensures that autonomous systems can regain secure operation without relying on continuous shore-based support.