Model based steganalysis

In this paper, we consider a new method for performing steganalysis using a statistical model of the cover medium. Using model based methodology, examples of detecting secret message and estimating the secret message length of bit-streams embedded using JSteg-like steganography and quantization index modulation are proposed. This steganalysis technique is based on the model of statistical distribution of quantized DCT coefficients. The histogram of cover image and "shrinkage histogram" are estimated from stego image using the statistical model. Then the secret message is detected and the secret message length is estimated. The methodology described in this paper is a framework which can also be applied to virtually any type of media such as JPEG2000 file format embedding.