Cloud Security Alliance unveils Zero Trust guide for OT/ICS

The Cloud Security Alliance (CSA) has released a new paper titled Zero Trust Guidance for Critical Infrastructure, addressing the application of Zero Trust principles within operational technology (OT) and industrial control systems (ICS).

The paper was developed by CSA's Zero Trust Working Group and focuses on bridging the gap between traditional information technology (IT) security methods and the specific demands of critical infrastructure sectors, which are increasingly vulnerable to cyber threats due to digital transformation. This transformation involves the merging of OT and IT systems, demanding more sophisticated security solutions.

Zero Trust Guidance for Critical Infrastructure provides a roadmap for implementing Zero Trust principles in OT/ICS settings. This includes CSA's recommended five-step process: defining the protect surface, mapping operational flows, building a Zero Trust architecture, creating Zero Trust policies, and monitoring and maintaining the network. These steps align with the best practices outlined in the NSTAC Report to the President on Zero Trust and Trusted Identity Management.

"A Zero Trust strategy is a powerful means of fortifying critical OT/ICS systems against increasingly sophisticated adversaries as it can keep pace with rapid technological advancements and the evolving threat landscape," stated Jennifer Minella, a lead author of the paper and a member of the Zero Trust Working Group leadership team. "It's our hope this set of guidelines will serve as a useful tool for communication and collaboration between those teams tasked with cybersecurity policies and controls and the system owners and operators of OT and ICS."

The document provides a detailed examination of the inherent differences between traditional IT and OT/ICS systems, including aspects such as network design, device diversity, and specific security requirements. It also supplies a step-by-step implementation guide with actionable insights for deploying a Zero Trust model in these settings. This includes guidance on identifying critical assets, mapping data flows, constructing a tailored Zero Trust Architecture (ZTA), policy formulation, and the nuances of continuous monitoring within an OT/ICS context.

Joshua Woodruff, another lead author of the paper and member of the Zero Trust Working Group leadership team, commented, "In an environment where security is paramount and also distinctly challenging, Zero Trust is not just a security upgrade but a necessity. By delineating practical strategies and specific methodologies tailored for implementing a Zero Trust strategy into CI environments, we are helping to ensure resilience and security amidst a rapidly evolving digital technology and threat landscape."

The CSA's Zero Trust Working Group continues to develop standards for achieving consistency across cloud, hybrid, user endpoint, and OT/ICS/IoT environments. Their discussions range from Zero Trust benefits and architecture to automation, maturity models, publication reviews, and industry events. The group invites individuals to join in future research and initiatives.