| In modern war, fast, timely and accurate transmission of geospatial data through the Internet will be a new requirement of the future battleground for geographic information system. However, due to the openness and sharing of computer networks, geospatial data is facing illegal browsing, theft and tampering and other security issues. Information Hiding Technology conceals the existence of secret information, and hides secret information to the general file without being discovered, thus ensuring the content and behavior of invisibility. To ensure data security, we use information hiding technology to achieve distribution of geospatial data through networks. As a next-generation video codec standard, H.264 has been rapidly gaining popularity and widespread application. Therefore, the combination with H.264 standard and video information hiding geospatial data has some practical significance.This paper analyzes and summarizes recent technique of H.264 video information hiding based on the researched results. On the study of geospatial data hiding, the thesis researches the shortcomings and tendency of existing H.264 video information hiding technology, combining the needs of geospatial data network distribution, this article makes a deep research on H.264 video steganography algorithms. The main works are as the following:1. A geospatial data sharing method based on Hamming code has been proposed. For secure transmission problems of geospatial data, combined with secret sharing ideas, introducing Hamming codes in the process of the secret sharing, which effectively solves the bit error and dropped frames that may be caused by transmission. This method implements geospatial data security, accuracy, and ensure the accuracy of the data. Finally, the simulation results show the safety and effectiveness of the method, the next step is to embed the data2. For the low capacity of information hiding for compressed video, a video steganography method is proposed based on H.264 Compressed Domain. Based on a combination of steganography bit control and distribution of image texture, steganographic encoding matrix algorithm is improved, which achieves large capacity, fast embedding and extraction. A deep analysis of advantages and disadvantages of the existing video steganography has been made, and this method effectively improves the steganographic capacity. Meanwhile, selecting embedded position accord to the distribution of image texture feature can improve the imperceptibility. Finally, the simulation results were compared with similar algorithms and analysis to verify the effectiveness of the algorithm.3. For video may encounter packet loss problem, this thesis designs a set model of dual protocol channel based on secret carried video transmission. The model incorporates H.264 network adaptability, based on the deep study of the H.264 video transmission process and transport protocol mechanism. This method uses a parser to separate blocks with secret from the secret carried video. Modules which containing secret information are transmitted via the TCP protocol, the remaining part of the transmission using UDP protocol, and two cache are constructed in the beginning and end of UDP, to avoid the loss of confidential information and achieve the integrity of confidential transmission. Experimental results achieve a complete transmission of secret carried video, and transmission frame loss is not found.4. For the hiding and transmission of geospatial data, this paper designs a model of data hiding and transmission. In the experiment, we simulate and test the transmission process using Direct Show and Qual Net, which verifys the reliability and effectiveness of the prototype system and record the video hiding capacity, embedding time, changing rate of video, transmission time and packet loss statistics, and integrity verification. Test and verification results show that this prototype system can realize hiding and effective transmission of geospatial data. |
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