Garrison: A Defensive Overlay Network for Critical SCADA Infrastructure Networks

Legacy SCADA installations that drive critical infrastructure remain exposed to nation–state–level cyber-physical attacks. Garrison inserts a lightweight gateway overlay that quarantines unpatchable devices, coordinates ephemeral addresses through a permissioned blockchain, and validates plant state with model-driven, proof-based Byzantine Fault Tolerant (BFT) consensus. Evaluations on a gas-pipeline model and a hyper-realistic US state power-grid simulator show that Garrison thwarts reconnaissance, foils gas-siphon and voltage-collapse attacks, and sustains 500–700 tx/s with < 100 ms end-to-end latency.