Securing the Digitally Managed Water Supply

Water system managers increasingly operate in distributed information exchange environments characterized by internal and external data communications. These sensor-controller-machine intensive environments must communicate internally (within and between device-level rings, within and between subsystems, and/or within and between systems) and externally (with and between original equipment manufacturers and/or with and between credentialed third parties). In critical infrastructure, cyber risk is magnified due to the heterogeneous nature of the technologies, protocols, and standards. Such an environment requires an approach that goes beyond information technology practices incorporating the unique needs of operational technologies. Protecting blended topologies requires a multi-dimensional framework integrating logical segmentation, cyber hygiene, network oversight, and human reliability. Logical segmentation compartmentalizes the network to align with service delivery. Cyber hygiene provides intrusion detection/prevention, identity services, malware protection, and network behavior analysis. Network oversight monitors network activity detecting and automatically responding to non-compliant actions with response policies that are service delivery fail-safe cognizant. Human reliability recognizes the potential for inadvertent and/or purposeful harmful actions and places digital safeguards at critical points to avoid compromise. Each dimension is significant itself but, collectively, they dramatically reduce the potential for gap and blind-zone formation with technologies and practices that are deployed in industrial and control system network operations today. This paper summarizes recent cyber-physical threat events and describes best practices in use across small and large critical infrastructure enterprises. Findings highlight the role network architecture design and operational practices to reduce attack surfaces and, at the same time, increase operational efficiency, ensure data integrity, and provide operational resilience in the face of evolving threats to cyber-physical systems.