Improved payload location for LSB matching steganography

The steganalysis of least significant bit (LSB) matching steganography has been well realized by many highly sensitive detectors so far, but few of them can analyze further to higher levels. Most of current steganalysis methods still stay in the low-level stage that can only detect the existence of secret message. In this paper, we focus on higher level steganalysis and an improved method for payload location of LSB matching is proposed. Our work is based on the combination and improvement of previous techniques including message length estimation and payload location. The proposed method first solves a regression problem to estimate the embedding rate utilizing steganalysis features. Then, the embedding payload can be located via optimal cover estimation and improved residuals calculation, in which the embedding rate achieved above is a crucial parameter. By this approach, the payload location method can be applied to practical use needless of any prior knowledge. Experimental results show that the proposed method outperforms the state-of-the-art work with a higher accuracy for payload location of LSB matching.