A two-layer steganography scheme using Sudoku for digital images

Steganography is a skill to convey the secret data in the digital images without getting any unexpected notices to attackers. LSB replacement, the simplest method, directly replaces the secret bits with LSB bit plane. Unfortunately, it is insecure because it cannot resist against the visual attacks and statistic detection. In 2009, Lin et al. proposed a novel data embedding scheme by using the concept of Sudoku. Lin et al.'s scheme not only improved the performances of traditional LSB-based steganography schemes, but also resist against steganalysis. In this paper, a steganography scheme based on Lin et al.'s scheme is explored. Experimental results show that the proposed scheme can improve the visual quality of stego-images. In addition, the average of hiding capacity is 1.29 bpp (bits per pixel). Therefore, it confirms that our proposed scheme provides higher hiding capacity than that of LSB replacement 0.29 bpp. Furthermore, our method shows the positive results to resist against the visual attacks.