Flaws in generic watermarking protocols based on zero-knowledge proofs

Abstract

Recently, two generic watermarking protocols were proposed, based on a popular zero-knowledge identification protocol. In this paper, we show that both protocols are flawed and therefore fail to achieve their purpose of allowing a prover to prove to a verifier of his ownership of a watermarked image. We also give some suggestions to fix these flaws. © Springer-Verlag Berlin Heidelberg 2005.