Collusion-secure Patchwork Embedding for Transaction Watermarking.

Digital transaction watermarking today is a widely accepted mechanism to trace back copyright infringements. Here, copies of a work are individualized by embedding user-specific watermark messages. One major threat on transaction watermarking are collusion attacks. Here, multiple individualized copies of the work are compared and/or combined to attack the integrity or availability of the embedded watermark message. In this work, we show how Patchwork embedding can be adapted to provide a maximum of resistance against collusion attacks at reduced payload and improved robustness.