CRYPTOGRAPHY

The word cryptography was coined from two Greek words ‘Krypto’, meaning hidden and ‘graphein’ meaning writing. Thus, cryptography means hidden writing. Cryptography is the method of protecting important data and information from third parties called adversaries or the public. It is also known as encryption. Modern cryptography is basically based on Mathematics and Computer science. The roots of cryptography are found in Roman and Egyptian civilizations. Hieroglyph is the oldest cryptographic technique. Based on security needs and threats, various cryptographic methods such as symmetric key cryptography, public key, private key, microdots, etc are adopted [1]. It is a two step process; encryption and decryption. The encryption process uses a cipher (code) in order to encrypt plaintext and convert it into ciphertext. Decryption is the opposite of encryption that is to decode the encrypted message or information. Cryptography was used extensively in the American Revolutionary War, the First World War and the Second World War. For example if the code was ‘CVVCEM’ then it would mean ‘ATTACK’. The initials of each letter is shifted by two places. This paper is basically a survey paper and we have studied the importance, features, advantages, and disadvantages and authenticated on the topic cryptography. Note: This paper is a REVIEW PAPER.