In a world racing toward digital transformation, the need for sustainable, intelligent, and secure systems is greater than ever. This volume unites pioneering research and practical innovations in cyber-physical systems (CPS) powered by IoT, Blockchain, AI, and post-quantum cybersecurity to tackle pressing environmental, industrial, and societal challenges. Contributions from global experts cover blockchain-enabled IoT architectures, energy-aware cybersecurity, explainable AI, and federated learning for edge devices, with applications in healthcare, aviation, finance, and smart agriculture. Each chapter blends real-world insights with forward-looking strategies for resilient, scalable, and green systems. Highlights include: Integration of Blockchain, IoT, and AI for secure, scalable, and sustainable CPS. Green, energy-efficient technologies such as sustainable encryption and low-power threat detection. Advanced AI techniques-explainable AI, federated learning, deep SHAP-for cybersecurity and personalization. Applications spanning healthcare, agriculture, aviation, finance, and legal systems. Post-quantum cryptography strategies for future-proof security. Human-centered, interdisciplinary approaches emphasizing usability, observability, and ethics. Ideal for researchers, practitioners, policymakers, and students, this collection offers a comprehensive roadmap to the sustainable convergence of the physical and digital worlds-building a smarter, safer, and more eco-conscious future.