ABSTRACT

Cryptography is the art of transforming the information into unreadable or unintelligible format. Based on key, Cryptography is classified as symmetric key or asymmetric key. Since the use of internet has been increased over the last few years so the value of exchanged data has increased. Cryptography is one of the type of computer security that converts the data from normal form to coded form. The main task of cryptography is to increase the data confidentiality and security by hiding the information, so that it cannot be accessed by unauthorized user. This paper provides relative study of different symmetric key algorithms such as data encryption standard (DES), triple data encryption standard (3DES), advanced encryption standard (AES) and blowfish.