This paper is to present a new image steganography technique based on quantum walks (QWs). In the proposed technique, the secret image is a gray-scale and the cover is a color image. The main contribution of QWs is to select one channel from (RGB) of the cover image that will host the secret bits. The performed analysis provides the proposed approach a strong base in the field of image steganography. The mean values of the results obtained based on analysis are as follows: PSNR is 48.5978, SSIM is 0.9964, UIQ is 0.9727, NCC is 0.996, and the capacity is 2-bit/pixel.
Quaternions are hyper-complex numbers applied in three-dimensional space, which are widely used in physics and image processing. In this paper, we utilize the features of quaternions for constructing a new substitution box (S-box) based on Lorenz system. The performance of the proposed S-box is investigated by S-box evaluation criterion. The results demonstrate that the constructed S-box has significant qualities for viable applications in security purposes. As well as, a new image watermarking mechanism is introduced which its embedding procedures based on the suggested Sbox. Experimental results demonstrate the efficiency of the presented image watermarking technique.