Cyber–Physical Resilience: Evolution of Concept, Indicators, and Legal Frameworks

The protection of critical infrastructures (CIs) from cyber–physical threats and natural hazards has become increasingly vital in modern society, which relies heavily on the essential services provided by these infrastructures. The European Union has emphasized the importance of this issue by deploying a comprehensive policy package in 2022, including the NIS2 and CER Directives. This paper explores the concept of resilience in critical entities and essential services from a cyber–physical perspective. It addresses the inherent complexity of CIs and discusses challenges, limitations, and future research directions for enhancing their protection in line with EU policies. Furthermore, it introduces a conceptual model of resilience, outlining its analytical dimensions, and reviews current resilience indicators and corresponding assessment frameworks.