适于实时传输的AVS视频码流加密算法*

为应对日益严重的盗版问题，提出了一种针对AVS标准的视频信息加密算法。通过加密运动矢量，使得视频图像重建时无法找到匹配的参考块，并通过误差扩散，引起视频图像错乱，从而达到对视频信息加密的目的。加密算法不改变码流结构，因此，接收端未经解密的视频码流可以由标准解码器正常解码，但是解码重建的视频图像质量明显下降，而经解密的视频重建图像可完全恢复到加密前的水平。实验结果表明，提出的加密方案具有良好的加密效果，其算法复杂度低，对编码效率影响也很小，基本上不影响视频的主客观质量。

Digital video encryption in AVS compressed stream for real-time transmission

Given the increasingly serious problem on copyright piracy,presented a video encryption method for the AVS standard. By encrypting the motion vectors,it was impossible to achieve the corresponding reference blocks in reconstruction. Furthermore,utilized error propagation to confuse the images.Thus video data could be encrypted efficiently.Such an algorithm brings no change to the structure of the data stream, so it could be decoded by a normal decoder without decrypting,but decreased the quality of the reconstructed image obviously.However, the reconstructed image by decoding with decrypting was almost the same as the original one.Simulating results show that the presented encrypting method has low complexity, trivial impact on coding efficiency, and almost no degrading on the subjective and objective video quality.