A New Approach to Countering Ambiguity Attacks

Watermarking based ownership dispute resolution schemes are vulnerable to a simple, but effective class of attacks, called ambiguity attacks, which cast doubt on the reliability of resulting decision by exploiting the high false-positive rate of the watermarking scheme. To mitigate such attacks, the authors propose a new scheme that embeds multiple watermarks, as opposed to embedding a single watermark, while constraining the embedding distortion, and detects a randomly selected subset of them during an ownership proof. The crux of the scheme lies in both watermark generation, which deploys a family of one-way functions, and selective detection, which injects uncertainty to detection process.