The Research On Video Content Encryption Algorithms And Watermarking Algorithms For HEVC Video

With the rapid development of Internet technology and multimedia technology,the storage and communication of digital video data become very convenient and fast.However,it brings people convience as well as serious video security problems,such as the leaking of video confidential contents,the illegal use of video copyright and etc.Therefore,people have put forward video encryption,video watermark and video control access to solve these problems in storage and transport.HEVC is the latest video coding standard,which can get a lower bitrate than H.264.As the encoding of HEVC is different from that of H.264,in coding unit,improved intra coding mode,advanced prediction mode and etc,the existed security schemes for H.264 cannot directly be used for HEVC.The main works of this thesis include:(1)A selective encryption scheme for HEVC based on Rossler chaotic system is proposed.In this scheme,the pseudo random binary sequence generator is first constructed based on Rossler chaotic system.After that,the generated key stream is used to encrypt the motion information and residual coefficients of HEVC.Especially for the encryption of residual coefficients,the improved scrambling effect is achieved by encrypted DC coefficients.Experimental results and analysis show that the proposed scheme can produce a good encryption effect,and keep the encrypted stream format-compliant.(2)A reversible watermarking scheme combining encryption in high efficiency video coding(HEVC)is proposed.According to characteristics of HEVC,the sign and amplitudes of motion vector difference(MVD),and the signs of residual coefficients are encrypted by RC4 stream cipher system.The watermarking algorithm that is reversible and the amplitude of nonzero alternating current(AC)residual coefficients are used.Experimental results and analysis show that the proposed scheme can obtain a good video security performance,keep the video stream format-compliant and increase a little size of the video stream file by the number of watermarking information.(3)Based on the above two video security schemes for HEVC,an video security system for HEVC is designed and developed.It can provide a experimental test platform for the further research on video security algorithm.The selective encryption scheme and reversible watermark combing encryption can strengthen the HE VC video security protection,and can be widely used for video content protection and copyright certification.