H.264 Video Selective Encryption Communication System Based On Chaotic Encryption Algorithm

With the rapid development of mobile Internet and information compression technology,the transmission and communication of video information has become very convenient.Realtime video communication has become an important way for people to communicate.A large number of video data about individuals,governments and enterprises need to be generated,processed,transmitted and accessed through the Internet.However,due to the openness and sharing of the network,there are many security risks in the transmission of video data,such as privacy disclosure,video theft,malicious tampering of video content.Therefore,the secure communication of real-time video has become the focus of research.In actual application scenarios of the real-time video confidential communication,encrypted videos must meet three performance indicators: security,real-time,and format compatibility.To satisfy these requirements,an improved bitstream-oriented encryption(BOE)method based chaotic encryption for H.264/AVC video is proposed.Meanwhile,an ARM-embedded remote real-time video confidential communication system is built for experimental verification in this thesis,the works are as follows:1.In the algorithm design,a 4-D self-synchronous chaotic stream cipher algorithm with cosine anti-controllers(4-D SCSCA-CAC)is designed to enhance the security.The algorithm solves the security loopholes of existing self-synchronous chaotic stream cipher algorithms applied to the actual video confidential communication,which can effectively resist the combinational effect of the chosen-ciphertext attack and the divide-and-conquer attack.2.In the video encryption scheme design,to meet the format compatibility of encrypted video,syntax elements of the H.264 bitstream are analyzed in real-time.Motion vector difference(MVD)coefficients and direct-current(DC)components in Residual syntax element are extracted through the Exponential-Golomb decoding operation and entropy decoding operation based on the context-based adaptive variable length coding(CAVLC)mode,respectively.the DC components and MVD coefficients are encrypted by the 4-D SCSCA-CAC,and the encrypted syntax elements are re-encoded to replace the syntax elements of the original H.264 bitstream,keeping the format compatibility.3.In the hardware implementation,hardware codecs and multi-core multi-threading technology are employed to improve the real-time performance of the hardware system.Finally,experimental results show that the proposed scheme,with the advantage of high efficiency and flexibility,can fulfill the requirement of security,real-time,and format compatibility simultaneously.