Non-interactive Watermark Detection for a Correlation-Based Watermarking Scheme

Cryptographic techniques have been deployed to securely prove the presence of a watermark in stego-data without disclosing any security critical information to the detecting party. This paper presents a detailed practical construction and implementation results of a correlation-based non-blind watermarking scheme in the non-interactive zero-knowledge setting. We extensively describe the modifications and hurdles that had to be overcome to transform a well-known watermarking scheme – whose general detection principle is applied in many other known schemes – into a two-party setting where the critical detection input, i.e. the watermark vector and the original data is cryptographically concealed from the verifying party using a commitment scheme. Our prototype implementation is very efficient and is an evidence of the practical feasibility of zero-knowledge watermark detection.