Critical infrastructures, protection and resilience

This chapter introduces the concept of Critical Infrastructure (CI). Although old civilisations had CI, the protection and resilience of CI has come to the fore again in the last two decades. The risk to society due to inadvertent and deliberate CI disruptions has largely increased due to interrelation, complexity, and dependencies of these infrastructures. The increased use of information and telecommunication technologies (ICT) to support, monitor, and control CI functionalities has contributed to this. The interest in CI and complex systems is strongly related to initiatives by several governments that from the end of the 90s of the previous century recognised the relevance of the undisturbed functioning of CI for the wellbeing of their population, economy, and so on. Their policies highlighted early the increasing complexity of CI and the challenges of providing such CI services without disruption, especially when accidental or malicious events occur. In recent years, most national policies have evolved following a direction from protection towards resilience. The need for this shift in perspective and these concepts are also analysed in this chapter.