Enhancing the Security and Quality of LSB Based Image Steganography

Abstract

This work is concerned with implementing Steganography for images, with an improvement in both security and image quality. The one that is implemented here is a variation of plain LSB (Least Significant Bit) algorithm. The stego-image quality is improved by using bit-inversion technique. In this technique, certain least significant bits of cover image are inverted after LSB steganography that co-occur with some pattern of other bits and that reduces the number of modified LSBs. Thus, less number of least significant bits of cover image is altered in comparison to plain LSB method, improving the PSNR of stegoimage. By storing the bit patterns for which LSBs are inverted, message image can be obtained correctly. To improve the robustness of steganography, RC4 algorithm has been used to achieve the randomization in hiding message image bits into cover image pixels instead of storing them sequentially. This process randomly disperses the bits of the message in the cover image and thus, making it harder for unauthorized people to extract the original message. The proposed method shows good enhancement to Least Significant Bit technique in consideration to security as well as image quality.