A Practical, Almost Zero-knowledge Watermark Verification Algorithm

摘要

Digital watermarks embed hidden information directly in media content, such as audio, video and images, typically in a way that is imperceptible to a human viewer. This embedded information can be used to handle copyright control, verify or authenticate, and establish ownership. It is therefore important that these watermarks be invisible, robust, and private to guard against attacks. Unfortunately, once a watermark is employed as evidence of ownership, enough information about the watermark may have been disclosed, rendering it vulnerable to removal attacks. Thus, the idea of zero-knowledge watermarking, of verifying the presence of a mark without revealing information about it, helps to address this issue. In this paper, we discuss an alternative, more practical approach to the complicated zero-knowledge watermarking protocols that have been proposed. We also analyze the probabilities of successfully cheating the system, and discuss the use of a black box detector tool.