This book describes the detailed concepts of mobile security. The first two chapters provide a deeper perspective on communication networks, while the rest of the book focuses on different aspects of mobile security, wireless networks, and cellular networks. This book also explores issues of mobiles, Io T (Internet of Things) devices for shopping and password management, and threats related to these devices. A few chapters are fully dedicated to the cellular technology wireless network. The management of password for the mobile with the modern technologies that helps on how to create and manage passwords more effectively is also described in full detail. This book also covers aspects of wireless networks and their security mechanisms. The details of the routers and the most commonly used Wi-Fi routers are provided with some step-by-step procedures to configure and secure them more efficiently. This book will offer great benefits to the students of graduate and undergraduate classes, researchers, and also practitioners.