Securing the Lifelines: CISA’s New OT Connectivity Principles Checklist

Operational Technology (OT) networks are the invisible backbone of our critical infrastructure, powering everything from energy grids to manufacturing plants. As the lines between IT and OT continue to blur, driven by demands for increased efficiency and remote accessibility, the imperative to secure these environments has never been more urgent. The Cybersecurity and Infrastructure Security Agency (CISA), in collaboration with the United Kingdom’s National Cyber Security Centre (NCSC-UK), has stepped up to this challenge, releasing comprehensive guidance on Secure Connectivity Principles for Operational Technology environments.

Published on January 14, 2026, this vital framework addresses the mounting pressure on asset owners to balance enhanced network connectivity with robust cybersecurity. It’s no longer a question of if OT networks will connect to broader IT infrastructures, but how securely. This new CISA checklist provides a critical roadmap.

The Imperative for Secure OT Connectivity

Historically, OT networks operated in air-gapped isolation, a physical barrier providing a degree of inherent security. However, this model is increasingly unsustainable in modern industrial environments. The drive for real-time data analytics, remote monitoring, predictive maintenance, and cloud integration necessitates bridging the divide between OT and IT. This convergence, while offering significant operational advantages, also introduces a vast new attack surface that threat actors are eager to exploit.

Attacks targeting OT often have far more severe consequences than typical IT breaches, potentially leading to physical damage, environmental hazards, service disruptions, and even loss of life. Consider the impact of a compromised control system in a power plant or a water treatment facility. The CISA and NCSC-UK principles directly confront these risks by advocating for a structured, security-first approach to OT connectivity.

Key Principles of the CISA/NCSC-UK Framework

While the full document includes a detailed checklist, the core principles revolve around establishing a resilient and defensible architecture for connected OT environments. These principles guide organizations in making informed decisions about how to securely integrate their industrial control systems (ICS) with enterprise networks and beyond.

• Minimizing Attack Surface: This principle emphasizes reducing unnecessary connections and services, segmenting networks effectively, and implementing robust firewall rulesets. The less exposed an OT system is, the fewer opportunities malicious actors have to gain unauthorized access.
• Establishing Trust Boundaries: Clearly defined trust zones between different segments of the network (e.g., between IT and OT, or between different OT zones) are crucial. This often involves the use of demilitarized zones (DMZs) and secure gateways that enforce strict access policies.
• Secure Remote Access: Recognizing the necessity of remote operations, the guidance stresses the importance of multi-factor authentication (MFA), secure VPNs, and privileged access management (PAM) solutions for all remote connections to OT systems. Without these, remote access becomes a significant vulnerability.
• Proactive Threat Detection and Response: Even with the best preventive measures, breaches can occur. The principles advocate for continuous monitoring of OT networks for anomalous behavior, logging of critical events, and developing incident response plans specifically tailored to OT environments.
• Lifecycle Security Management: Security is not a one-time configuration but an ongoing process. This includes secure-by-design principles for new systems, regular patching and vulnerability management, and continuous assessment of security posture.

Remediation Actions: Implementing Secure Connectivity

Adopting these principles requires a strategic and systematic approach. Organizations managing OT environments can take several concrete steps:

• Conduct a Comprehensive Risk Assessment: Begin by understanding the specific risks associated with your OT infrastructure, including potential attack vectors and the impact of successful breaches.
• Segment Networks: Implement strong network segmentation between IT and OT, and within OT networks themselves. Use industrial firewalls and data diodes where appropriate to control traffic flow rigorously.
• Implement Secure Gateways/DMZs: Design and deploy secure gateways between IT and OT networks, ensuring that all data transfer is controlled, inspected, and validated using protocols appropriate for OT.
• Strengthen Access Controls: Enforce the principle of least privilege for all users and systems accessing OT. Implement strong authentication methods, including MFA, for both local and remote access.
• Patch Management for OT: Develop a robust patching strategy that considers the unique challenges of OT systems, which often cannot tolerate downtime for updates. This may involve staged rollouts, temporary backups, or specialized OT patching solutions.
• Monitor and Log OT Activity: Deploy specialized OT security monitoring tools to detect unusual network traffic, unauthorized commands, and deviations from normal operating parameters. Log all critical events for auditing and forensic analysis.
• Employee Training and Awareness: Educate all personnel, from IT to OT engineers, on cybersecurity best practices, social engineering tactics, and the specific risks associated with OT environments.
• Develop Incident Response Plans: Create and regularly test incident response plans specifically designed for OT cybersecurity incidents. These plans should include procedures for containment, eradication, recovery, and communication.

Conclusion: A Proactive Stance on OT Security

The CISA and NCSC-UK Secure Connectivity Principles Checklist is not merely a set of recommendations; it is an essential guide for navigating the complex landscape of connected Operational Technology. By embracing these principles, organizations can move beyond reactive security measures to adopt a proactive posture, safeguarding critical infrastructure from an ever-evolving threat landscape. The future of industrial resilience hinges upon our ability to integrate robust security at every layer of OT connectivity.