Modified YASS algorithm with virtual host block selection and model based embedding

Yet Another Steganography Scheme (YASS), a promising steganographic scheme for JPEG images which can resist blind steganlysis via embedding data in randomized locations. However, the randomization is not sufficient enough, as some positions are possible to hold host blocks and some are definitely not. Meanwhile, the artifacts introduced by quantization index modulation (QIM) embedding led to the weakness for its unsafety. In this paper, to overcome these drawbacks, we present a modified YASS scheme incorporated with further randomized virtual host block selection and the model based embedding which permutes secret bits by a low-density cover probability to minimize differences between the distribution of a cover image and that of the stego. Consequently, the proposed scheme can survive the attack made by the specific steganalyzer for YASS. Experimental results demonstrate that the detection probability achieved by the specific steganalyser on our proposed method is less than 59%, while is about 95% and above on YASS.