Cryptography is a technique or method to secure personal data from unauthorized user. In cryptography two types of operation are performed. (i) Encryption and (ii) Decryption. To encrypt and decrypt data a secret key is used. After encryption original data is converted into another format known as cyphertext, which is not easy to understand. In the present era everyone needs fast processing and less space required to store results in computation process as well as security of information. There are many encryption algorithms in which some of these take more computation time, some of these take less, but all has their own advantages and disadvantages. Mainly encryption are classified into two based on key used are: asymmetric key encryption and symmetric key encryption. Asymmetric key Encryption is also called public key cryptography. In this, two different keys are used, one is for encryption called public key and decryption is performed by another key termed as a private key. It is not so easy to guess or interrupt both public key and private key as well as to gain access to the information. In the asymmetric key encryption, all the recipients have their public key and sender has its own private key, which is kept secret from everyone. Symmetric key encryption is also known as private key encryption. A single key is used to encrypt and decrypt the plain text. Private Key makes the encryption process faster. But secret key cryptosystem has suffered from the problem of