This book proposes robust solutions for securing a network against intrusions for data privacy and safety. It includes theoretical models, commercialization of validated models, and case studies. Explains the integration of technologies such as artificial intelligence, the Internet of Things, and blockchain for network security in a 6G communication system. Highlights the challenges such as spectrum allocation and management, network architecture and heterogeneity, energy efficiency and sustainability, antenna, and radio frequency. Discuss theories like quantum-safe cryptography, zero-trust networking, and blockchain-based trust management. Covers emerging technologies including homomorphic encryption, secure multi-party computation, post-quantum cryptography, and distributed ledger technology for security and privacy in 6G communication systems. Presents light and deep secure algorithms to detect fake incidents in wireless communication. The text is primarily written for senior undergraduates, graduate students, and academic researchers in fields including electrical engineering, electronics and communications engineering, and computer science.