Circumvention of watermark analysis in a host content

摘要

Methods and devices are provided to thwart analysis of a watermarking system by preventing analysis of watermarks in a host content. Upon receiving a content at a watermark embedding device, the content is analyzed to ascertain whether one or more test features are present in at least a first portion of the received content. When the analysis reveals that one or more test features are present, embedding of watermarks in at least the first portion of the received content is disabled. The test features of interest include a temporal, a spatial and/or a frequency characteristic such that, if a region of the content that includes test feature is embedded with a watermark, at least one characteristic of the embedded watermark is detectable upon analysis of that region. The test feature can, for example, approximate an impulse signal, a step function signal or a pure sinusoidal signal.

主权项

1. A method for prevention of discovery of watermark secrets in a watermark embedding system, the method comprising:
receiving a content at a watermark embedding device, the content comprising a plurality of digital content samples; analyzing the digital content samples using a processing device to ascertain whether one or more test features are present in at least a first portion of the received content, the test features specially designed such that when the specially designed test features are embedded with watermarks, the embedded test features enable extraction of at least one secret parameter of the embedded watermarks through analysis of the embedded test features; and upon a determination that the one or more test features are present, disabling embedding of watermarks in at least the first portion of the received content.