基于ARM7的数字视频加解密系统研究

为了在资源受限的ARM7嵌入式平台里实现数字视频加解密系统功能，在达到较好信息隐藏目的同时而不带来庞大的计算量是本文所关注的重点. 加密算法方面，本文采用了基于Arnold变换和骑士巡游变换相结合的复合置乱算法. 在算法软件实现时，本文对系统开销较大的骑士巡游算法进行了改进，找到一种基于映射表的方法，有效地避免了原算法不停查找巡游矩阵，从而大幅降低ARM7内核的系统开销，将处理一帧图像的速度提高了30倍左右. 最后，给出了基于ARM7目标板进行加解密实验的结果分析.

Reaserch of Digital Video Encryption and Decryption System Based on ARM7

As ARM7 processor has limited capability of processing digital videos，this article has proposed a new way to implement the video encryption and decryption system based on ARM7 processor. The way that can encrypt the important information of video very effectively costs little calculation of processor and prevents the attacks from hackers.This implementation is based on the composite algorithem of Knight-tour transform and Arnold transform which can benefit from each other.As Knight-tour transform costs lots of calculations of CPU，this article has found a good way based on LUT（Look-up table）to reduce costs of calculation. The experiment based on ARM7 target has approved that the speed of processing a frame of vedio has been improved up to 30 times with the way from this article for encryption.