Blockchain-Driven Zero-Trust Architectures for Critical Infrastructure

In an era of escalating cyber threats that increasingly target critical infrastructure, there is growing urgency to protect operational technology (OT) systems in energy and utilities. By uniting the core tenets of zero trust security—where every request is inherently untrusted until verified—with the decentralized transparency of blockchain, we can significantly reduce the risk of undetected breaches or insider misuse. This paper explores how blockchain-based authentication and smart contracts, aligned with guidelines such as NIST SP 800-207, can create a tamper-evident ledger of all access requests and device interactions. The goal is to move beyond reactive defenses and instead implement continuous validation of assets and their privileges. This approach not only mitigates the lateral movement of threats within industrial control systems but also enables streamlined auditing of regulatory requirements (e.g., NERC CIP).