Cryptography plays a major role in securing data. 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 in information security as it refers to all hardware and software function, characteristics, features, 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 together provide the fundamentals for trusted e-commerce and secure communication. There is a broad range of cryptographic algorithms that are used for securing networks and presently continuous researches on the new cryptographic algorithms are going on for evolving more advanced techniques for secures communication.