This book provides a comprehensive survey of state-of-the-art techniques for the security of critical infrastructures, addressing both logical and physical aspects from an engineering point of view. Recently developed methodologies and tools for CI analysis as well as strategies and technologies for CI protection are investigated in the following strongly interrelated and multidisciplinary main fields: - Vulnerability analysis and risk assessment - Threat prevention, detection and response - Emergency planning and management Each of the aforementioned topics is addressed considering both theoretical aspects and practical applications. Emphasis is given to model-based holistic evaluation approaches as well as to emerging protection technologies, including smart surveillance through networks of intelligent sensing devices. Critical Infrastructure Security can be used as a self-contained reference handbook for both practitioners and researchers or even as a textbook for master/doctoral degree students in engineering or related disciplines.More specifically, the topic coverage of the book includes: - Historical background on threats to critical infrastructures - Model-based risk evaluation and management approaches - Security surveys and game-theoretic vulnerability assessment - Federated simulation for interdependency analysis - Security operator training and emergency preparedness - Intelligent multimedia (audio-video) surveillance - Terahertz body scanners for weapon and explosive detection - Security system design (intrusion detection / access control) - Dependability and resilience of computer networks (SCADA / cyber-security) - Wireless smart-sensor networks and structural health monitoring - Information systems for crisis response and emergency management - Early warning, situation awareness and decision support software