一种结合H.264/AVC CABAC熵编码器特征的视频选择性内容加密算法

为了对数字视频内容进行快速高效加密，提出了一种新的选择性内容加密算法.在H.264/AVC的场景自适应算术编码（CABAC）熵编码器的“二进制算术编码”阶段引入伪随机化.通过CABAC熵编码器的M编码器，自身完成视频数据单元的加密操作，无需额外的加密模块.实验表明：新算法不会降低CABAC熵编码器的压缩效率，加密后的视频码流有效地隐藏了源视频的可视信息.

A Selective Video Content Encryption Algorithm Exploiting the Characteristics of H.264/AVC CABAC Entropy Encoder

In order to solve the encryption computing efficiency and flexibility issues when applying traditional data cryptographic algorithms on video content protection, this paper proposed a new selective video content encryption algorithm which exploits the characteristics of H.264/AVC CABAC entropy encoder. By introducing pseudo randomization in CABAC entropy encoder’s binary arithmetic encoding stage, the new algorithm can employ the entropy encoder itself to fulfill the basic encryption operation. In the meantime, the video content data unit being encrypted can be selected flexibly according to its importance. The experimental results show that the proposed algorithm does not impair the compression efficiency of the entropy encoder, and the encrypted video stream hides the visual characteristics of the original video content successfully.