Research Of Covert Communication Based On Information Hiding

Information hiding is a novel technique in the field of information security in this years, and it is significant to covert communication. The covert communication technology means using information hiding techniques to embed secret data into common carrier with positions which did not raise any suspicion by one's ears and eyes. And then, the carrier with secret is transmitted in open channels. Compared to traditional encryption techniques, covert communication adds a safeguard and hides the existence of the secret data. Through the speech and the webpage, people can easily transmit information and obtain knowledge. Therefore, research on data covert communication based on speech and webpage are very important in information security and secure communication.Several information hiding algorithms are mainly studied based on real-time speech and webpage. Experimental results show that those algorithms have high invisibility and security. In addition, they can be also applied to covert communication.Firstly, investigation on information hiding was described in detail. The basic knowledge of covert communication technology is introduced based on speech and webpage.Secondly, a kind of information hiding algorithm of improved LSB is designed and realized based on real-time speech. The synchronization coding and subsection techniques are applied in the algorithm. The algorithm has high hiding capacity and invisibility. It can meet real-time requirements to embed 6400 bits confidential information in a second.Thirdly, an algorithm of webpage information hiding based on invisible character is designed to improve the robustness and the capacity. Compared to traditional invisible characters webpage information hiding algorithm, the new approach can not only keep the hiding effects, but also increase the hiding capacity up to 3.5 times. And the algorithm can resist on much more attacks of web slim-fast.Finally, innovative thinking is considered on how to utilize the web annotation statements to hide secret data in webpage. Then, an algorithm of webpage information hiding based on the annotation statements is presented. According to the secret bit value for embedding, the specific annotation statement was chosen to insert in front of the start tag. The algorithm has high invisibility and security.