The practice and study of methods for secure communication in the presence of hostile third parties is known as cryptography. It consists of construction and analysis of protocols to prevent third parties from reading private messages. Some of the important aspects of cryptography are data integrity, data confidentiality, authentication and non-repudiation. There are several applications of this field of study such as digital currencies, military communications and electronic commerce. The field of cryptography consists of different areas of study like symmetric-key cryptography and public key cryptography. The sphere of study which seeks to detect insecurity or weakness in a cryptographic scheme is known as cryptanalysis. This book provides significant information of this discipline to help develop a good understanding of cryptography and related fields. Those in search of information to further their knowledge will be greatly assisted by this book. It will serve as a reference to a broad spectrum of readers.