An intriguing field of study that exists at the convergence of computer science, mathematics, and electrical engineer-ing is cryptology. Due to the rapid pace of cryptology's development, it is difficult to keep up with everything. The theoretical underpinnings of the field have been fortified over the past quarter-century; we now have a firm grasp of security definitions and methods for demonstrating the security of structures. Additionally, rapid advancements are observed in the field of applied cryptography, where obsolete algorithms are compromised and withdrawn, while novel algorithms and protocols arise. Cryptography has infiltrated virtually every aspect of life, including medical implants, cell phones, bank cards, automobiles, and email programs. Research have made significant strides in securing these two applications. This represents a significant departure from the historical practice of restricting cryptography to extremely specific applications, such as financial systems and government communications. The pervasiveness of crypto algorithms has necessitated that an expanding number of individuals comprehend their operation and practical applications. This matter is tackled in this book through the provision of an all-encompassing introduction to applied cryptography that is suitable for both students and industry professionals.