This book explores the critical role of security protocols in safeguarding modern digital infrastructure, offering a comprehensive examination of their design, implementation, and management. Covering foundational concepts, real-world case studies, emerging technologies, and future trends, it provides readers with a deep understanding of how secure communication is achieved and maintained across networks, devices, and services. Designed for cybersecurity professionals, network engineers, and students alike, the book emphasizes best practices, compliance, and resilience in an ever-evolving threat landscape.