Collusion-Resistant Media Watermarking via Statistical Transformation
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Solution Overview
Problem
Existing digital watermarking technologies face challenges in resisting collusion attacks, where multiple copies of media content with unique watermarks are combined to corrupt or remove the watermark, making it difficult to trace piracy sources.
Innovation Solution
A collusion-resistant system generates multiple copies of media content with different transformations applied to each, ensuring that when combined, the output has downgraded quality, making pirated content unattractive, while maintaining quality and watermark detectability for legitimate users.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple copies of media content with unique watermarks are distributed to trace piracy, then the ability to identify piracy sources is improved, but colluders can combine these copies to corrupt or remove watermarks, making detection difficult
Solution Approach 1:
The patent segments the media content into multiple transformed copies, each with different transformations applied (e.g., color space conversions, geometric transformations, noise additions). This segmentation ensures that when colluders combine copies, the transformations cause misalignment and degradation, protecting the watermark detection accuracy while distributing content to legitimate users.
2Object-affected harmful factors
If transformations are applied to media content copies to prevent collusion attacks, then the quality of combined pirated content is degraded, but the transformations must not degrade the quality for legitimate users or the watermark detectability
Solution Approach 1:
The patent applies different transformations to different regions or aspects of the media content in a controlled manner. The transformations are designed to be imperceptible to human viewers (maintaining local quality for legitimate users) but accumulate significantly when multiple transformed copies are combined by colluders, thereby degrading the quality of pirated content while preserving the user experience.
Solution Approach 2:
The patent changes various parameters of the media content copies such as color space representations, brightness levels, contrast ratios, and geometric properties. These parameter changes are carefully controlled to remain imperceptible individually but create cumulative degradation when combined, effectively reducing the attractiveness of pirated content while maintaining reliability for legitimate users.
Data Source
AI summary
Techniques for reducing piracy of media content are described. In some embodiments, a collusion resistant method is performed at a device, where the device receives a first request for a base copy of a media content item. In response, the device determines a first transformation based on a statistical performance criterion and a viewing performance criterion. The device further generates a first copy of the media content item by replicating and applying a first transformation to the base copy, where the first copy of the media content item satisfies the viewing performance criterion, and the first copy of the media content item is statistically different from the base copy or other copies in accordance with the statistical performance criterion. The device then causes transmission of the first copy of the media content item in combination with a first watermark for the base copy of the media content item.