| Information hiding is the technology to hide the presence of communications by embedding the additional secret messages into the digital cover media under the premise of not seriously degenerateing the cover media. The information hiding technology has become a hot interest and field as an important part of information security. The video-sharing platform is designed to provide services to uers on Internet, such as browsing, searching, creating and sharing videos. As the main business of the Internet streaming media, large numbers of videos are shared through the video-sharing websites, which makes the application of covert communication possible.By analyzing the re-encoding mechanism of the video-sharing platform, the disseration studies and designs a covert communication tool based on video-sharing platform by using the method of information hiding in videos. The main contributions include:(1) The concepts, theories, basic elements, applications and state-of-art are summarized.(2) The re-compression mechanism of several video-sharing websites is analyzed by uploadingvideos with different parameters. Based on it, the scheme to avoiding some attacks such as frame-dropping, clipping and watermark-adding attack is given.(3) In order to ensure the robustness, the algorithm to hide information in the spatial domain of videos is given, which is based on direct sequence spread spectrum. Using the method, the embedding and extracting scheme based on single frame of videos is designed.(4) The covert communication tool based on video-sharing platform is designed and implemented, and the results of preliminary tests on Youku and Tudou show that the the tool is effect.Finally, a summarization of the dissertation is given and the future work is prospected. |
