An efficient video encryption scheme for H.264 compressed bitstream

In this paper, the bit-sensitivity of H.264 bitstream has been studied firstly, to determine the most significant bits for video reconstruction. On this basis, an efficient video encryption scheme in H.264 compressed domain is presented. In the proposed scheme, the most significant bits in H.264 bitstream are directly extracted to be encrypted, including the codewords of intra-prediction modes, motion vector difference (MVD) and the sign bits of the low frequency DCT coefficients of intra-frames. Experimental results show that the proposed encryption scheme exhibits reliable perceptual security, can secure against not only replacement attacks but also brute-force attacks, and achieves significant computational efficiency. Furthermore, it maintains the format-compliance to the H.264 standard decoder and has no impact on the compression efficiency.