This book, divided into three parts, describes the detailed concepts of Digital Communication, Security, and Privacy protocols. In Part One , the first chapter provides a deeper perspective on communications, while Chapters 2 and 3 focus on analog and digital communication networks. Part Two then delves into various Digital Communication protocols. Beginning first in Chapter 4 with the major Telephony protocols, Chapter 5 then focuses on important Data Communication protocols, leading onto the discussion of Wireless and Cellular Communication protocols in Chapter 6 and Fiber Optic Data Transmission protocols in Chapter 7. Part Three covers Digital Security and Privacy protocols including Network Security protocols (Chapter 8), Wireless Security protocols (Chapter 9), and Server Level Security systems (Chapter 10), while the final chapter covers various aspects of privacy related to communication protocols and associated issues. This book will offer great benefits to graduate and undergraduate students, researchers, and practitioners. It could be used as a textbook as well as reference material for these topics. All the authors are well-qualified in this domain. The authors have an approved textbook that is used in some US, Saudi, and Bangladeshi universities since Fall 2020 semester - although used in online lectures/classes due to COVID-19 pandemic.