Date Added: Apr 2012
In this paper, the authors present a classification of network security techniques such as: secrecy, authentication, non-repudiation and integrity control. The secrecy techniques are two categories: cryptography and steganography. Steganography like cryptography is a very useful technique to achieve secrecy in communication. If both cryptography and steganography are used then the communication becomes two fold secured. All the major techniques on image steganography proposed by different researchers are discussed very briefly. The techniques on audio steganography are also briefly discussed. Finally a hybrid model is shown using both cryptography and steganography.