**Preface to "Cyber Security and Critical Infrastructures"**

Critical infrastructures are essential for national public security, economic well-being and national security. Critical vulnerabilities in such infrastructures are increasing with the proliferation of information technology. As critical infrastructures become more vulnerable to cyber-attacks, protecting them has become an important issue for any organization or country. Due to the apparent impact of such conditions, the risks to ongoing operations, such as failure to upgrade legacy infrastructure or failure to comply with required regulatory regimes, are high.

With the rapid proliferation of complex cyber threats targeting critical infrastructures, which have a significant disruptive impact, cybersecurity for critical infrastructures is an important issue for academics, professionals and policy-makers. The effective cybersecurity managemen<sup>t</sup> of critical infrastructures requires a comprehensive overview of the technical, political, human and behavioral aspects. Furthermore, the coronavirus pandemic poses new challenges for companies adapting to business models in which working from home has become "the new normal". Businesses are accelerating digital transformation and cybersecurity is now a major concern.

This book presents manuscripts that were accepted after a careful peer-review process for publication in the topic "Cyber Security and Critical Infrastructures" by the Applied Sciences, Electronics, Future Internet, Sensors and Smart Cities MDPI journals. The book includes sixteen articles: an editorial, fifteen original research papers describing current challenges, innovative solutions and real-world experiences involving critical infrastructures, and one review paper focusing on the security and privacy challenges in Cloud, Edge, and Fog computing.

> **Leandros Maglaras, Helge Janicke, and Mohamed Amine Ferrag** *Editors*
