Research On Video Integrity Authentication Based On Fragile Watermarking

In recent years, with the rapid development of digital multimedia information and broadband network popularization, multimedia information spreads more and more convenient. Digital watermarking technology is the important means of realizing integrity certification which is the important question of information security research. Digital watermarking technology is the hot spot of multimedia copyright protection research, and video watermarking is key and difficult. Based on the discrete cosine transform in the watermarking technology application methods, combined with its own characteristics and MPEG video compression technology, the paper proposes the video fragile watermarking algorithm based on original streaming video DCT and MPEG compression technology. The main research work and contributions of this thesis are summarized as follows:1. This thesis systematically summarizes the concepts, technique requirements, typical applications and research status of video watermarking techniques, and analyses the key technique, including the generation of the watermark, watermarking embedding, attacking and testing standards etc. Based on these, the thesis researches several typical video watermarking algorithms which take advantage of the good energy-frequency character of the DCT.2. According to characteristics of DCT, The thesis presents a scheme for the color video integrity authentication based on fragile watermarking. The RGB color mode is transformed to YST color mode which using for embedding watermarking into original video. According to the relationship of the quantized DCTcoefficients of the frames, the authentication codes are created, as watermarking is embedded into the image by modifying the last non-zero DCT coefficient. The video anthentication is carried out without referencing to the original video, blind detection can be achieved. The simulation results show that the scheme could keep video’s quality and also can detect the tamper and attack on original video.3. Combining with space domain and DCT domain watermarking, a scheme for the color video tamper detection and restoration based on fragile watermarking is proposed. The embedded watermarking consists of image block authentication data and restoration data. In the process of watermarking generation, according to the top five most significant bits of RGB three color components, the authentication data and restoration data are generated, as watermarking is embedded into the last three bits of the mapping blocks. The tamper detection is carried out without referencing to the original video, blind detection can be achieved. Extracting the watermarking which embedded into mapping blocks to determine whether the original image block was tampered and can be restored the tampered areas. The simulation results show that the scheme could keep video’s quality, and also can complete integrity authentication, tamper positioning and approximate restoration of tampered areas.