Cryptography is the interesting study of different methods of secure communication. It concentrates on making and analyzing protocols which secure the information or message from outsiders or adversaries. It is the amalgamation of mathematics, electrical engineering and computer engineering. This book is compiled in such a manner, that it will provide in-depth knowledge about the theory and practice of cryptography. While understanding the long-term perspectives of the topics, the book makes an effort in highlighting their impact as a modern tool for the growth of the discipline. Coherent flow of topics, student-friendly language and extensive use of examples make this text an invaluable source of knowledge.