On estimation of secret message length in JSteg-like steganography

Recenty, image steganalysis has attracted more attention. In this paper, a new method for detecting the secret message and estimating the secret message length of bit-streams embedded using J-Steg like steganography is proposed. First, based on the model of statistical distribution of quantized DCT coefficients, the histogram of the cover image is estimated from the stego image. Then, the secret message is detected as well as the estimation of the secret message length using the estimated cover histogram. Interestingly, our study on steganalysis of J-Steg like embedding offers a proof of Zhang et al. ´s method (2003). The methodology described in this paper is a framework which can also be applied to many other stegaographic methods such as JPEG2000 file format embedding.