Secure spread spectrum watermarking for multimedia

TLDR

The authors propose a tamper‑resistant watermarking algorithm that embeds an independent, identically distributed Gaussian random vector as a spread‑spectrum watermark into the perceptually dominant spectral components of images, with a methodology extendable to audio, video, and other multimedia. The watermark is inserted imperceptibly into the most significant spectral components, providing robustness against lossy compression, filtering, conversion, requantization, and common geometric transformations when the original image is available for registration, and it resists collusion attacks through Gaussian noise. Experiments confirm that the detector reliably identifies the owner under these conditions, and the paper discusses remaining open problems.

Abstract

This paper presents a secure (tamper-resistant) algorithm for watermarking images, and a methodology for digital watermarking that may be generalized to audio, video, and multimedia data. We advocate that a watermark should be constructed as an independent and identically distributed (i.i.d.) Gaussian random vector that is imperceptibly inserted in a spread-spectrum-like fashion into the perceptually most significant spectral components of the data. We argue that insertion of a watermark under this regime makes the watermark robust to signal processing operations (such as lossy compression, filtering, digital-analog and analog-digital conversion, requantization, etc. ), and common geometric transformations (such as cropping, scaling, translation, and rotation) provided that the original image is available and that it can be successfully registered against the transformed watermarked image. In these cases, the watermark detector unambiguously identifies the owner. Further, the use of Gaussian noise, ensures strong resilience to multiple-document, or collusional, attacks. Experimental results are provided to support these claims, along with an exposition of pending open problems.