# Critical Infrastructure **Domain:** Infrastructure / Security / Public Policy **Doc Type:** Concept Node **Maturity:** Developed ## Definition **Critical infrastructure** consists of systems whose incapacity or destruction can produce disproportionate harm to public safety, continuity, economic life or institutional function. Criticality is relational rather than a permanent property of an object. A modest component can become critical when many systems depend on it, substitutes are unavailable or recovery time exceeds the tolerance of the functions it supports. ## Governing Variable The governing variable is continuity of essential function under disturbance. ## Material and Institutional Manifestation Power, water, telecommunications, transport, finance, health, food, government services and computation can become critical through dense dependency. Ownership may be public or private; operational responsibility and public consequence often cross that boundary. ## Computational Analogue Dependency graphs, failure domains and service-level objectives make some critical relations machine-readable. The model remains incomplete if it ignores labor, repair supply chains, legal authority or informal workarounds. ## Constitutional Question and Failure Modes Security can justify secrecy, but excessive opacity can prevent public accountability and shared learning. Other failure modes include common-mode dependencies, deferred maintenance, capture by operators and protection plans that preserve assets while abandoning dependent communities. ## Related Ontology [[wiki/Infrastructure as Executable Social Order|Infrastructure as Executable Social Order]] · [[wiki/Utility Infrastructure|Utility Infrastructure]] · [[wiki/Infrastructure as Power|Infrastructure as Power]] · [[wiki/Cyber-Physical System|Cyber-Physical System]] ## Simple Reminders, Quotations, and Thoughts > “How will we build the tools to maintain the software in long-lived online devices that can kill us?” > **— Ross Anderson**, *2018 Edge Annual Question, question* [[reminders/Cybernetics/How Can We Maintain Software in Long-Lived Devices That Can Kill by Ross Anderson|How Can We Maintain Software in Long-Lived Devices That Can Kill by Ross Anderson]] ## Relationships - **Edge source and reminder relationship:** [[collections/Edge|Edge]] records the original Edge Annual Question responses; the source-checked quotations below route to their individual reminders and back to this topic.