Cryptography has proven to be one of the most contentious areas in modern society. For some, it protects the rights of individuals to privacy and security. For others, it puts up barriers against the protection of our society. This book aims to develop a deep understanding of cryptography and provide understanding of how privacy, identity provision, and integrity can be enhanced with the usage of encryption. The book has many novel features including: full provision of web-based material on almost every topic covered; provision of additional on-line material such as videos, source code, and labs; and coverage of emerging areas such as Blockchain, Light-weight Cryptography, and Zero-knowledge Proofs.