The first section of the book lays a strong groundwork for understanding IoT security, exploring areas such as attack modelling, intrusion detection, fraud prevention, and secure communication protocols. It also discusses advanced defenses for 5G-powered IoT networks and the integration of Software-Defined Networking (SDN). The second section focuses on IoD, examining critical topics like authentication, trust management, access control, and ethical considerations in drone-based surveillance. By combining theoretical perspectives with practical applications, this book provides a holistic approach to securing the connected world.