Introduction of Cryptography

Abstract

Cryptography or cryptology is the practice and study of techniques for secure communication in the presence of third parties. Cryptography is about constructing and analyzing protocols that prevent third parties or from the public to access private messages various aspects in information security such as data confidentiality, data integrityand authentication. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, and digital communication engineering. Applications of cryptography include ATM cards, military encryptions, computer passwords, and electronic commerce. Keywords: cryptography; Symmetric Key; Asymmetric Key; Encryption and decryption; hash function; Public key; Enigma Machine.