Research And Implementation Of Content-Based Video Encryption Scheme With The Adaptive Technology

With the the security issues of video transmission and play is more and more aroused people's attention.In order to meet the needs of video security for various applications,in recent years,according to the character:istic of video data,a variety of video encryption algorithms and its improved schemes was proposed by scholars.Based on the study of a variety of previous typical encryption algorithm,combining with the current video requirements of high transmission efficiency and played with multi-level quality,this thesis proposes an adaptive encryption algorithm.The algorithm has the features as follows:(1)This algorithm differs from the previous traditional encryption algorithms,it takes the adaptive discriminant mechanism based on the video content,depending on the content of the video scenes,encryption the syntax elements selectively,so it also can effectively meet the video encryption requirements with different application scenarios and different content.(2)The key stream of this algorithm is produced by the Logistic map,the different levels of adaptive encryption are implemented based on the different video content,through this way it can improve the efficiency of encryption,overall less the expansion of data.The encryption syntax elements include:Intra-Prediction-Mode,Motion-Vector-Difference and residual transform coefficients.(3)Ingeneral,the traditional video encryption algorithm can make the expansion of coding date with range of 20%to 50%and the expansion of time with range of 10%to 20%.While the algorithm designed in this thesis combined strictly with the encoding process,on the premise of guarantee of safety,based on the experiments with a lot of different source video files in a variety of practical cases for many times,it prove that the algorithm could control the expansion of coding date within the range of 4%to 6%and control the expansion of time within the range of 2%to 6%.(4)Becauseof the encryption algorithm adopted the discriminant mechanism based on the significance of the video content,it can choose encryption scheme reasonably,according to the video content,so that it can significantly reduce the encryption to redundant data,reduce the complexity of the encryption algorithm and improve the efficiency of compression coding.