The Research Of Video Information Encryption Technology

Video, as the most conversant information carrier with personal sense, has been used widely in politics, economy, military, education, medical, journalism, and so on. With the development of multimedia and network technology, the security of video information is of the greatest importance than before. Therefore, how to insure the information secure and integrated is still considered to be a challenging issue. In order to protect the confidentiality, integrity, and authenticity of video information, the fast and efficient video information encryption schemes have recently gained more attention in both academia and industry. The focuses of this thesis are video information security, and the video encryption algorithms are studied based on the practical application and encoder process. The main research contents and contributions in this dissertation are as follows:1. An adaptive lightweight video encryption scheme based on the H.264/AVCTaking the diversity of video application situation, security demand and computing resource into account, an adaptive lightweight video encryption algorithm is proposed based on the special feature of the H.264 video coding standard. To choose some key information to encrypt in order to tradeoff the restrict relation of security, compression ratio and encryption speed, and etc. The intra prediction, the signs of the motion vector difference, and the luminance transform coefficients of residual data before entropy coding are adjustably partially encrypted by stream cipher. The proposed algorithm can be adaptive to encrypt based on the safety level and practical needs to ensure the safety of texture information and motion information of videos. Experimental results demonstrate the proposed algorithm can achieve good security and high efficiency, obtain low complexity and time cost, as well as maintain of data format constant in various degrees.2. An encryption algorithm based on the entropy coding for video transmission applicationTo meet the security demand of video transmission application, the entropy coding with Context-Adaptive Variable Length Codes (CAVLC) and Exponential-Golomb Variable Length Codes in baseline profile are analyzed. Combined with the video compression and encryption, a video encryption scheme based on the entropy coding for transmission application is presented based on entropy theory. The encryption scheme is compose of coded block pattern permutation, sign of trailing ones scrambling and levels of nonzero coefficients encryption. The important syntax elements and sensitive coded elements are chosen to encrypt using mathematical operations, permutation and stream ciphers. Experimental results show that the presented algorithm can achieve high security and low complexity and time cost, as well as have a little effect on the transmission bandwidth. So it is suitable for security video services for mobile device and wireless application in the baseline profile, such as video telephony, video conferencing and wireless communications.3. A video encryption algorithm based on the CABAC coding for video storage applicationIn order to protect video storage application in the main profile, the video encryption algorithm based on the CABAC coding are proposed according to analyzing the performance of entropy coding. To maintain the performance of compression, the less of the key initial context indexes are dynamically encrypted by chaotic encryption system to disturb the distributing of context model. Experimental results show that the chaos algorithm which is sensitive by initial conditions and randomness by chaotic parameters can enhance the security performance. The proposed algorithm can provide more reasonable security, and have a little effect on the compression ratio by less than one in a thound, which satisfy the requirement of the television broadcasting and streaming media potential applications of the storage application.4. An efficient security multimedia system on embedded platformAn efficient security multimedia system on embedded platform is designed by analyzing the hardware architecture and resource, the efficient DSP-based H.264/AVC coding is studied by efficient video coding techniques and system optimizing implementation. To protect the confidentiality and integrity of media information, a novel security mechanism is presented, which includes user identify authentication and video encryption algorithm. Experimental results show that the proposed hardware framework has high performance and achieves a better balance between security and efficiency. What's more, encoding and encryption at the same time, the performance of data process can meet real-time application.