Study On Information Hiding For Compressed Video

The security requirement of secret information transmission has become urgent in digital age. The traditional cryptography technology encrypts the protected information to get the cipher-text which is hard for understanding. Though the cipher-text is hard to understand, it would leak the existence of encryption behavior and absorb the attackers’ attention. The attackers would intercept, break or replay the cipher-text and bring a serious threat to the secret information transmission. Data hiding can make the existence of secret information unnoticeable by hiding it into those common files. Using public digital covers to transmit information secretly can protect not only the content of the information but also the secret behaviors (encryption and transmission). H.264/AVC video encode/decode standard has gained popularity rapidly for its high compression efficiency and outstanding network-friendly property, and has become one of the most conventional ways for video transmission. Thus, it has been one of the research focus in the filed of information security in study compressed video information hiding technology based on H.264/AVC.The compressed-domain steganography algorithm for video based on H.264/AVC has been studied in this paper. The main work is as follows:A new information hiding algorithm with prediction mode modulating for H.264video is proposed. The author considers the intra prediction coding features of the H.264/AVC standard. Secret information is embedded by modifying intra prediction modes of intra-4×4blocks during the mode decision process. The proposed scheme can effectively improve the capacity of hidden information by using a new data hiding method during the process of information hiding. In addition, the quality of the stego-video is also and improved by simplifying the mapping rules and modifying the intra prediction modes according to the cost function during intra prediction process. The experimental results show that the proposed scheme can effectively improve the capacity of hidden information with little bit rate and no quality degradation.A information hiding scheme for H.264video in VLC domain is proposed. The information is embedded into the last tailing coefficient of4X4blocks during the context-based adaptive variable length coding (CAVLC) process. The main advantages of the proposed algorithm is that the bit-rate has no change after information embedding, and the hidden information can be easily extracted with the low computational complexity.