基于密钥矩阵序列的视频乱序加密方法

Video Encryption by Permutation Based on Key-matrix Sequence

提出RMSP(Random Matrix Sequence Permutation)方法,同时完成帧内宏块(Macro Block,MB)之间、块内VLC(Variable Length Coding)码字之间双重互补的乱序加密,并利用随机序列生成随机乱序密钥矩阵序列,供每帧和每块依次用不重复的密钥矩阵对MB和VLC码字乱序。RMSP方法完全保持编码格式和压缩率,具有对应序列密码的抗攻击能力且明文信息完全隐藏的特点,速度快约四倍,适用于MPEG、H.26x及JPEG等主流编码信号加密,可制作单独模块。

This paper proposed an algorithm called RMSP （Random Matrix Sequence Permutation）. M Bs （MacroBlock） were shuffled in each frame and VLC codewords were permuted in each block. The two synchronously implemented permutations could complement each other. Random sequences were utilized to generate a random key matrix sequence used as one-time pad permutation tables. Compared with directly encrypting video data using stream cipher, the algorithm has the same strong antiattack ability while keeping compression ratio and format-compliance, and its speed is about four times faster than the stream cipher method using the same random sequences. The experimental results demonstrate that the encrypted video is fully disguised. The algorithm is applicable to MPEG, H. 26x, and also to JPEG coded signal, and can be made as separate modular.