Zero Trust Architecture

Zero-trust architecture is a security model that grants no implicit trust based on network location and verifies every access request by identity, device posture, and context before allowing it. The reference definition is NIST SP 800-207, published August 2020, built on the maxim never trust, always verify. For shipping it counters the flat, perimeter-trusting networks common on vessels, where reaching the bridge LAN historically implied access to everything; micro-segmentation, strong authentication, and least privilege limit lateral movement after a phishing or supply-chain breach. Full zero trust is hard on legacy OT, so it is usually applied first to shore and IT systems.