Operational technology: Securing legacy OT systems with Zero Trust

This briefing recommends adopting a Zero Trust approach to protect legacy OT systems that cannot be easily patched or replaced. It outlines the risks introduced by IT/OT convergence and remote access, and recommends practical controls—complete asset visibility, least-privilege access, network segmentation and micro-segmentation, deny-by-default application control, and tightly managed remote access—that can be layered around legacy devices to reduce risk without disrupting critical operations.