基于熵编码加密的MPEG视频加密算法研究

MPEG Video Encryption Algorithm Based on Entropy Encoding and Encryption

针对现存算法在安全性和压缩比方面的不足 ,提出一种基于熵编码加密的 MPEG视频加密算法 .此算法在熵编码过程中 ,通过加密码字在 Huffm an编码表中的序号 ,实现加密编码 .与置乱 Huffman编码表和置乱 Huffman树方法相比较 ,具有更大的置乱空间 ,具有更高的安全性 .实验表明 ,此算法对压缩比的影响比 DCT系数加密算法小 ,计算复杂度低、速度快 。

Proposed a novel fast MPEG video encryption algorithm according to the shortages of existed algorithms in security and compression ratio. This algorithm encrypts video data by encrypting the indexes of codewords in Huffman tables. Compared to the algorithms confusing Huffman trees and Huffman tables, the algorithm proposed here has bigger confusion space and is of higher security. Experiments show that, the algorithm has less effect on compression ratio than the algorithms confusing DCT coefficients do, and it is of low cost and high speed. Thus, it is suitable for secure video encoding with real-time requirement.