Secret Key Estimation for Image Sequential Steganograph in Transform Domain

Trivedi et al. presented an effective LMP (locally most powerful) method (2005) to estimate the secret key for sequential steganography in mid- and high-frequency of DCT domain. In this paper, we proposed an improved LMP algorithm, which not only can reliably estimate the secret key for mid- and high-frequency sequential embedding, but also for the case of low-frequency. Moreover, the application of improved algorithm for DWT sequential steganography is discussed. Results of experiment show the performance of improved algorithm is desirable for low-, mid- and high-frequency steganography in DCT domain and in the subbands of DWT domain.