Optimal Watermark Embedding and Detection Strategies Under General Worst Case Attacks

We revisit the problem of optimal watermark embedding and detection for computationally limited detectors under general attack channels. First, a formal definition of the problem is given for general attack channels under the Neyman-Pearson criterion of optimality. Later, asymptotically optimal decision regions are offered, assuming that the detector is computationally limited and that the attack channel is strongly exchangeable. These results are extended to general attack channels where random watermark sequences are considered. The optimal embedding rule is offered and the worst attack channel is identified.