ENHANCEMENT OF SECURED DATA TRANSMISSION USING n*3 INCOMPREHENSIBLE STEGO FILES BASED ON LS, SL, AND LC ALGORITHMS

Abstract

In this paper, security of covert communication is increased by using <i>n</i>^*3 incomprehensible stego files based on the novel algorithms, which are logical and statistical (LS), split logical (SL), and logical concealing (LC). Generally, cryptography and steganography techniques are used to achieve a secured data transmission. Cryptography is used to generate the "ciphertext" and steganography is used to produce the understandable stego image. The results of these two techniques alert the intruder to the fact that secret information is being exchanged. To overcome this drawback, this paper generates n*3 incomprehensible stego files with four levels of security using covert data and a container (cover) image. The main novelty of the proposed framework is that it provides multilevel security for data transmission by converting understandable stego images into non-understandable (incomprehensible) stego files. The LS encryption algorithm generates the lesser length of ciphertext with the input of covert data. The steganography generates a good visual quality of an understandable stego image by using discrete framelet transform (DFT) and random pixel embedding (RPE) techniques. Finally, the SL and LC algorithms produce <i>n</i>^*3 incomprehensible stego files using the understandable stego image. These stego files are incomprehensible, meaningless, and invisible in nature. The experimental results have shown that the incomprehensible stego files improve the payload capacity, quality metrics (peak signal-to-noise ratio, correlation, and number of pixels change in rate), and also four levels of security to the secret data. It is also able to face the various steganalysis attacks, such as files deletion, data deletion, and data modification.