The book "IT Convergence and Security" includes the proceedings of ICITCS 2021 and provides a comprehensive overview of the latest challenges in the field of IT convergence and security. It highlights the central role these topics play in current research as well as in industrial and commercial activities. The subjects covered range from machine learning and deep learning to communication and signal processing, as well as computer vision, future network technologies, artificial intelligence, and robotics. Additionally, it addresses software engineering, intelligent vehicle networks, healthcare, web technologies, the Internet of Things, and security and privacy aspects. This book is aimed at researchers in academia, industry, and other research institutions engaged in IT convergence and security.