The concept of "Critical Infrastructures" is constantly evolving in order to reflect current concerns and to respond to new challenges, especially in terms of (cyber)security and resilience. Protection of critical infrastructures against numerous threats has therefore developed into a high priority at national and EU level. During the last two decades a new type of threat has prevailed in the Critical Infrastructure threat landscape, that of cyberattacks; Protection against them is the primary focus of this paper. In order to do so the analysis first aims to drop some light into the differences between Critical Infrastructures and Critical Information Infrastructures, terms that are often confused, and to indicate possible inadequacies in the applicable protection regulatory regime. Finally, the health sector has been chosen as a sector-specific case in an effort to demonstrate how protection of a Critical Infrastructure, challenged as it has been with a constantly increasing number of cyber incidents, could be sufficiently protected in the new digitalised era.

The NIS Directive is the first horizontal legislation undertaken at EU level for the protection of network and information systems across the Union. During the last decades e-services, new technologies, information systems and networks have become embedded in our daily lives. It is by now common knowledge that deliberate incidents causing disruption of IT services and critical infrastructures constitute a serious threat to their operation and consequently to the functioning of the Internal Market and the Union. This paper first discusses the Directive's addressees particularly with regard to their compliance obligations as well as Member States’ obligations as regards their respective national strategies and cooperation at EU level. Subsequently, the critical role of ENISA in implementing the Directive, as reinforced by the proposal for a new Regulation on ENISA (the EU Cybersecurity Act), is brought forward, before elaborating upon the, inevitable, relationship of the NIS Directive with EU's General Data Protection Regulation.