Research On Steganography Method Of H.264

Because of the perceptual masking of human beings, Steganography can hide data in media file without being discovered, and it has been used in many fields, such as copyright protection, authentication. In this paper, according to the characteristics of H.264 coded video and thorough comprehension of steganography algorithm, we do the research on data hiding for H.264 video.On the aspect of data hiding, the researches are as following:To embed in coded video, we entropy decode it to find proper 4x4 luminance DCT blocks in I frames, and entropy encode it after secret bits was embedded.There are two embed methods were used: the first one is LSB, which used in DCT blocks with just low-frequency coefficients, the other is data hiding based on digital-position information, and it was used in blocks with middle and high frequency coefficients. Those two methods make best use of redundancy of DCT coefficients, and get higher capacity.On the other hand, considering the application environment of streaming media of H.264, we make backup copy of secret message and embed it the same, to preserve secret message against being damaged when there were packet-loss because of the bad network conditions, or attacks. And the order of embedding is encrypted, so it can stand against malicious frame delete.To verify the effective of the method, we do experiments based on the Windows xp sp2, using VC++6.0 software platform to realize secret embedding, fetching, backup, recovery, etc. The experiment shows a prefect result with good imperceptibility and recovery of secret message when loss rate is low.