Attributing Fake Images to GANs: Learning and Analyzing GAN Fingerprints (1811.08180v3)

Abstract: Recent advances in Generative Adversarial Networks (GANs) have shown increasing success in generating photorealistic images. But they also raise challenges to visual forensics and model attribution. We present the first study of learning GAN fingerprints towards image attribution and using them to classify an image as real or GAN-generated. For GAN-generated images, we further identify their sources. Our experiments show that (1) GANs carry distinct model fingerprints and leave stable fingerprints in their generated images, which support image attribution; (2) even minor differences in GAN training can result in different fingerprints, which enables fine-grained model authentication; (3) fingerprints persist across different image frequencies and patches and are not biased by GAN artifacts; (4) fingerprint finetuning is effective in immunizing against five types of adversarial image perturbations; and (5) comparisons also show our learned fingerprints consistently outperform several baselines in a variety of setups.

Attributing Fake Images to GANs: Learning and Analyzing GAN Fingerprints

The paper presented in this paper explores the pioneering concept of learning distinct fingerprints from Generative Adversarial Networks (GANs) for the purpose of image attribution. As GANs continue to advance in generating photorealistic images, the challenges they pose to visual forensics and intellectual property protection have become significant. This paper provides a comprehensive analysis and approach to recognizing unique GAN fingerprints, aiming to differentiate and attribute GAN-generated images to their respective sources.

Key Insights and Contributions

1. GAN Fingerprints for Attribution: The central hypothesis of the paper is that each GAN instance possesses a unique fingerprint reflective of its parameterization - including architecture, training dataset, and initialization seed. These fingerprints are stable patterns shared across images generated by the same GAN but are distinct across different GAN instances.
2. Experimental Findings:
   • Existence and Uniqueness: Experiments have shown that changes in any GAN parameter (architectural nuances, training data variations, initialization seeds) result in unique fingerprints. The paper establishes that even minor differentiations in the training regime leave distinct imprint patterns on generated images, enabling precise source attribution.
   • Persistence Across Frequencies: The persistence of GAN fingerprints across various frequency bands and patch sizes was examined. It was concluded that both low-frequency and high-frequency image components carry sufficient fingerprint information for attribution, with high-frequency components being more informative.
   • Artifacts and Robustness: To address concerns regarding attribution biases due to visual artifacts, the paper employed a perceptual similarity metric to identify and evaluate artifact-free image subsets. Furthermore, the methodology demonstrated the robustness of learned fingerprints against several adversarial perturbations such as noise, cropping, and JPEG compression.
   • Superiority of Learned Fingerprints: In comparative studies, the learned fingerprints consistently outperformed established methods, including recent PRNU-based fingerprint methodologies, in both classification accuracy and feature distinguishability.
3. Practical and Theoretical Implications: From a practical perspective, the proposed methods can enhance digital forensics, informing better attribution mechanisms for detecting potentially malicious GAN applications. Theoretically, the work encourages further examination into the model-specific artifacts left by deep generative models and their interpretability.
4. Future Directions: The paper suggests that future research might explore the potential of incorporating GAN fingerprinting technologies in broader applications like real-time image processing and forensic analysis. Additionally, expanding the paper to other categories of generative models could offer a more comprehensive understanding of model attribution mechanics.

Conclusion

This paper represents an important advancement in attributing GAN-generated images back to their model origins through fingerprinting. It highlights a promising path for both enhancing security measures against the misuse of GANs and safeguarding intellectual property rights associated with generative models. The deep exploration into the intricacies of GAN fingerprints sheds light on the potential for further developments in AI and digital forensics, ensuring accountability and authenticity in the field of synthetic image generation. The methodologies proposed could serve as foundational tools in addressing complex attribution challenges that arise within the evolving landscape of AI-generated content.