Tampering Detection in Compressed Digital Video Using Watermarking

We presents a method to detect video tampering and distinguish it from common video processing operations, such as recompression, noise, and brightness increase, using a practical watermarking scheme for real-time authentication of digital video. In our method, the watermark signals represent the macro block's and frame's indices, and are embedded into the nonzero quantized discrete cosine transform value of blocks, mostly the last nonzero values, enabling our method to detect spatial, temporal, and spatiotemporal tampering. Our method can be easily configured to adjust transparency, robustness, and capacity of the system according to the specific application at hand. In addition, our method takes advantage of content-based cryptography and increases the security of the system.