The main objective of this book is to introduce cyber security using modern technologies such as Artificial Intelligence, Quantum Cryptography, and Blockchain. This book provides in-depth coverage of important concepts related to cyber security. Beginning with an introduction to Quantum Computing, Post-Quantum Digital Signatures, and Artificial Intelligence for cyber security of modern networks and covering various cyber-attacks and the defense measures, strategies, and techniques that need to be followed to combat them, this book goes on to explore several crucial topics, such as security of advanced metering infrastructure in smart grids, key management protocols, network forensics, intrusion detection using machine learning, cloud computing security risk assessment models and frameworks, cyber-physical energy systems security, a biometric random key generator using deep neural network and encrypted network traffic classification. In addition, this book provides new techniques to handle modern threats with more intelligence. It also includes some modern techniques for cyber security, such as blockchain for modern security, quantum cryptography, and forensic tools. Also, it provides a comprehensive survey of cutting-edge research on the cyber security of modern networks, giving the reader a general overview of the field. It also provides interdisciplinary solutions to protect modern networks from any type of attack or manipulation. The new protocols discussed in this book thoroughly examine the constraints of networks, including computation, communication, and storage cost constraints, and verifies the protocols both theoretically and experimentally. Written in a clear and comprehensive manner, this book would prove extremely helpful to readers. This unique and comprehensive solution for the cyber security of modern networks will greatly benefit researchers, graduate students, and engineers in the fields of cryptography and network security.