A state-owned organisation responsible for a strategically important water infrastructure asset; operating an extensive system of dams, pumping stations, technological units, and monitoring centres engaged IRON OT. Together, the organisation’s components ensure water flow regulation and the protection of surrounding areas, making their secure and reliable operation essential.
The objective of the project was to design a comprehensive OT security architecture that ensures reliable communication between technological systems, secure integration with the IT environment, and overall cyber resilience in line with the requirements of the new cybersecurity legislation and the international ISA/IEC 62443 standard.
Prior to the project, it became evident that individual control systems had been developed incrementally and independently, often by different vendors. IT and OT infrastructures were interconnected without a unified security concept, lacking clear network segmentation and defined responsibilities for communication management. No architectural design addressing cyber resilience and operational reliability was in place. The contracting authority therefore required a comprehensive solution that would serve not only as a strategic framework but also as a foundation for a public procurement process for implementation.
Our task was to conduct a detailed analysis of the existing infrastructure and, based on this analysis, design a security architecture aligned with the requirements of modern OT environment management. The project began with detailed mapping of technological components and network relationships between PLCs, SCADA systems, communication channels, and control centres. This included the identification of risks, vulnerabilities, and critical components whose failure could threaten the operation of the water infrastructure.
Based on these findings, an architecture was designed in accordance with ISA/IEC 62443 principles, defining security zones and conduits, secure separation of OT and IT environments using a demilitarised zone (DMZ) and perimeter firewalls, a network topology with redundant communication paths, and controlled access points. The architecture also incorporated an access control and authentication model for operational staff and external contractors, with strong emphasis on sustainability, scalability, and secure remote access.
The project also included legal and organisational preparation for implementation. We developed documentation to support the public tender process, including technical and security requirements for suppliers, proposed contractual conditions defining responsibilities and access rules, and support during negotiations with representatives of the contracting authority and prospective suppliers. As a result, the design is not only technically feasible but also legally enforceable.
The outcome of the project is a comprehensive and auditable OT security architecture design that clearly defines the boundary between IT and OT environments, enhances cyber resilience, and provides a solid foundation for future modernisation. The client gained clear and practical documentation for secure implementation, along with assurance of compliance with legislative requirements and the ISA/IEC 62443 standard.
The project confirmed that a well-designed OT security architecture is a key factor in protecting critical infrastructure, where security, operational reliability, and legal certainty are just as important as the technology itself.