Abstract: It is used to ensure that the contents of a message are confidentially transmitted and would not be altered. Network security is most vital component of information security as it refer to all hardware and software function, characteristic ,feature ,operational procedures, accountability, access control, and administrative and management policy. Cryptography is central to IT security challenges, since it underpins privacy, confidentiality and identity, which to gather provide the fundamental for trusted e-commence and secure communication. There is a board range of Cryptographic algorithms that are used for securing network and presently continuous researcher on the new cryptography algorithm are going on for evolving more advanced techniques for secure communication.

Keywords: Cryptography, plain text, cipher text, encryption, decryption, network security.