A novel H.264 advanced video coding fragile watermarking method is proposed that enables the authenticity and integrity of the video streams to be verified. The effectiveness of the proposed scheme is demonstrated by way of experimental simulations. The results show that by embedding the watermark information in the last nonzero-quantized coefficient in each discrete cosine transform block, the proposed scheme induces no more than a minor distortion of the video content. In addition, we show that the proposed scheme is able to detect unauthorized changes in the watermarked video content without the original video. The experimental results demonstrate the feasibility of the proposed video authentication system.