Abstract: The development of cloud storage makes people willing to upload personal video to the cloud,but the data security problems brought by it have become increasingly prominent,selective encryption is one of the effective ways to protect video privacy.Aiming at the problem of insufficient security in the current H.264/AVC video selective encryption method,a novel H.264/AVC video selective encryption method based on adaptive permutation of macroblock coding information is proposed.The method adaptively generates pseudo-random sequence frame by frame according to the macroblock types,uses the pseudo-random sequence to randomly permute the coded block pattern (CBP) and the residual data in the coding information of a macroblock between macroblocks,changes the intra prediction modes of I macroblocks,and flips the signs of motion vector differences of P macroblocks and B macroblocks.Experimental results show that the proposed method can preserve format compatibility with H.264/AVC coding standard,and has characteristics of large encryption space,good key sensitivity,and small video bitrate variation.Compared with the existing encryption schemes,the proposed method performs better in terms of visual security and resistance to state of the art of sketch attack.

Key words: Adaptive permutation, Cloud service, Coding information, H.264/AVC, Selective encryption