Cryptography is the study of methods for secure communication, focusing on the design and analysis of protocols that protect information or messages from unauthorized access or adversaries. It is an interdisciplinary field that combines mathematics, electrical engineering and computer engineering. This book is a valuable compilation of topics, ranging from the basic to the most complex theories and principles in the field of cryptography. Different approaches, evaluations and methodologies, and advanced studies on the subject matter have been included herein. This book, with its detailed analyses and data, will prove immensely beneficial to professionals and students involved in this area at various levels.