Organizations in both public and private sectors have increasingly dependent on electronic data processing. Protecting these data is of utmost concern to the organizations and cryptography is one of the primary ways to do the job. Cryptography is a German word which means secret writing. Cryptography is necessary while communicating over any untrusted medium, which includes just about any network, particularly the Internet. Encryption and decryption algorithm's security depends on the algorithm as well as on the key's confidentiality, once the key is leaked, it means any one can encrypt or decrypt the data, it means the whole procedure become useless.