HYBRID DATA SECURITY: A REVIEW OF CRYPTOGRAPHY AND STEGANOGRAPHY TECHNIQUES

Abstract

As the use of computer networks and internet is ubiquitous, information security has become sizzling area of research in recent times. Data security is very crucial in exchange of information over computer networks because it secures the information from intruders. Although cryptography and steganography are two popular security mechanisms that could be used to provide data security, each of them has drawbacks. Cryptography encrypts the content of the message thereby making it difficult for intruders to fathom. Steganography on the other hand makes communication invisible, that is, message is embedded in a cover media in such a way that intruders cannot detect it existence. Cryptography problem is that, the cypher text looks meaningless, so the intruder can interrupt the transmission and use cryptanalysis to reveal the meaning of the message. Steganography problem is that once the presence of hidden information is revealed or even suspected, the message has become known. Therefore, effort in this paper was directed at reviewing various types of cryptography and steganography techniques. Also, a hybrid data security model was proposed by combining cryptography and steganography to improve information security leveraging on the strengths of the two techniques. In the proposed model, plain message was first encrypted using Data Encryption Standard (DES) making it cypher text. Secondly, the encrypted message (cypher text) was hidden in an image using Least Significant Bit (LSB) technique. The proposed model provided an enhanced data security scheme as attacker will not be able to detect the existence of the message hidden in the image and if per chance the message is discovered, the attacker will still not be able to make meaning of the content because the message was encrypted.