一种加密变长码字并保持视频格式的加密方案

A Format-compliant VLC Codewords Video Encryption Scheme

视频加密通常要求满足实时性和保持码流格式不变。而直接加密视频码流中的DCT系数和MV变长码字会产生非法变长码字从而破坏码流格式,不利于视频通信的正常应用。该文提出了一种加密DCT系数和MV变长码字并保持码流格式不变的方法。此方法同视频码流中定长码字的加密结合起来可以形成一个完整的视频加密方案,试验结果表明该方案满足视频通信实时性的要求并达到较高的保密级别。

Efficient encryption in real-time and maintaining compliance to the syntax of video stream is the essential requirement of video security. Direct encryption of VLC codewords will usually not result in valid VLC codewords and so the encrypted video stream is not format-compliant. A scheme is proposed that DCT and MV VLC codewords are encrypted while stream format is preserved. The experimental results show that the proposed scheme combining with the encryption of FLC codewords such as INTRADC, sign bits of DCT and MV using secret key cryptography algorithm can meet the real-time constraint and provide high security level.