Steganalysis of multiple-base notational system steganography

This letter presents a method for attacking multiple-base notational system (MBNS) steganography [1]. In the MBNS steganography, secret data are converted into symbols in a notational system with multiple bases. The pixels of a host image are then modified such that when the pixel values are divided by the bases, their remainders are equal to the symbols. Through analysis, we prove that the amount of small remainders increases due to the modification. Based on this observation, we propose a steganalytic approach which is effective in not only detecting MBNS steganography but also estimating its embedding rate.