This book equips readers with the essential knowledge to innovate and improve network performance while ensuring security and safety. It covers foundational TCP/IP Internet network technologies and significant cyber-attack case studies. Additionally, it explains the core technologies behind Bitcoin, Ethereum, blockchains, smart contracts, hash functions, and encryption. The book also explores advanced concepts such as reinforcement learning, generative AI, federated learning, and digital twin technologies, offering new approaches to enhancing network security and blockchains through these cutting-edge methods.