The Research Of Video Encryption Based On H.264/AVC Standard

With the rapid development of multimedia and network technology,video applications are experiencing rapid developments.To ensure that video contents can't be maliciously captured during transmission and saving,video encryption becomes a hot researching point in multimedia application field.H.264/AVC coding standard,as a new generation coding standard,is playing an important role in different multimedia areas due to its good compression performance and its good ability in adapting to network conditions.Therefore,researching on video encryption algorithms for H.264/AVC is of significant importance.Currently,there are already some selective encryption techniques which also take the video coding process into consideration.Since videos have big data,special coding architecture and also need to be transmitted in real time,different techniques have their own advantages and disadvantages and it's difficult to meet the requirements of practical applications by using only one strategy.Therefore,to realize the optimization and improvement of encryption process,researching on how to effectively combine the advantages of these strategies is the main research point of this paper.The contributions of this paper are as follows:First,we introduced some basic knowledge on H.264/AVC coding process and encryption.Moreover,we introduced and analyzed the status quo of this researching area and also analyzed some existing problems in current researches.Second,we propose a selective perceptual video encryption technique for H.264/AVC.The proposed technique combines both the transform coding stage encryption process and the entropy coding stage encryption process.Based on the fact that intra macroblocks and inter macroblocks have different effects on data restoration,we proposed to choose different syntax elements for them.Meanwhile,we proposed a macroblock-based secret key sequence generation strategy based on RC4 stream coding algorithm.Testing on JM10.2 platform,we find that the proposed method have quite high security level and quite low computational complexity.In addition,the proposed encryption process has little influence on the coding performance and the encrypted video sequences are operable.Third,existing encryption algorithms encrypt the video frames without classification and cause the computational complexity to be extremely high.To deal with this problem,we proposed an unequal encryption method based on regions of interests.In the proposed method,we treated the regions of interests as important regions and organized the macroblocks in the regions of interests into different slices according to the FMO strategy.Then we encrypted the data in different slices with different strategies.Experimental results show that the proposed method can protect the whole video frames,especially the important regions.It can strike a good balance between security and real-time.Therefore it can better meet the practical requirements.