An integrity authentication scheme for video bit-stream based on the fragile watermarking is proposed in this paper. In the compressed bit-stream of H.264

The authentication codeword are generated according to the mode of intra_4×4 in I_Slice firstly

and then embedded into B_Slice and P_Slice by modulating some VLC codeword of sub-block. This modulation is based on the mapping rule between the VLC codeword and the bit to be embedded. The mapped codeword is very similar to the original codeword

namely

the length of codeword is same and the value of coding element is similar. This scheme could detect the watermarking rapidly

which meets the requirement of the real-time processing of video. Experimental results show that it has less influence on the quality of video

and can effectively carry out the integral certification of video frame.