Collusion-resistant intentional de-synchronization for digital video fingerprinting

A powerful class of attacks in multimedia fingerprinting is known as collusion attacks, where a clique of colluders, each having a copy of the same multimedia content with different fingerprint, combine their copies to form a colluded copy. In this paper, we propose a countermeasure against collusion attacks for digital video: pseudo-random intentional de-synchronization techniques. Each user´s copy of video is slightly pseudo-randomly changed (de-synchronized) in such a way that these changes will not be noticeable for an individual copy, but will be significant enough to produce perceptual artifacts when multiple copies are combined (e.g., via averaging, replacement attacks, etc.). To achieve this task, we propose several novel effective techniques, including constrained random temporal and spatial sampling. We discuss feasibility issues and limitations of video de-synchronization, and present several examples.