Selective Encryption of H.264/AVC Based on Block Weight Model

The rise of 4K and 8K techniques has led to the growth of video data streaming. Consequently, the greater challenges of encryption efficiency and information leakage facing selective encryption (SE) makes it necessary to reduce the encryption ratio as much as possible. In this paper, we design a SE scheme for H.264/AVC video which achieves a trade-off between low encryption ratio and high safety, for both cryptographic attack and sketch attack point of view. As a starting point, we propose a novel calculation model, called block weight model that can take advantage of reference structure of a video sequence to quantitatively analyze the impact of each block on the motion compensation of other blocks. This calculation model can conduce to accurately select the key bytes in the compressed bitstream for encryption, which greatly retains the network friendliness and improves the efficiency compared to previous work. In addition, our scheme supports scalable encryption granularity by providing an adjustable encryption parameter to meet different security levels. Experimental results verified that our solution is highly efficient in protecting confidential video content with simple computation.