Differential Privacy of Gaussian Process Posterior Sampling
Summary
A study on Differential Privacy (DP) for Gaussian Process (GP) posterior sampling reveals that the intrinsic randomness of this process provides DP guarantees without requiring external noise. Researchers derived explicit Rényi-DP bounds, distinguishing between posterior-mean leakage and data-dependent posterior-covariance leakage, highlighting that effective ridge regularization is crucial for meaningful privacy. Empirical validation using membership-inference attacks demonstrated that leakage aligns with predicted dependencies on regularization, posterior variance, and the number of released sample paths. Utility experiments, particularly for downstream tasks like excursion-set estimation, showed that privacy-compatible regularization can maintain useful decisions with only modest utility loss, especially in noisy observation environments where the utility-optimal posterior is already substantially regularized. The findings also indicate that adding calibrated GP noise can further enhance these intrinsic DP guarantees.
Key takeaway
For AI Scientists developing or deploying Gaussian Process models with private training data, you should prioritize effective ridge regularization to achieve robust differential privacy. This intrinsic randomness-based approach offers meaningful privacy guarantees, particularly in noisy observation settings where utility loss is modest. Consider adding calibrated GP noise to further strengthen privacy without relying solely on posterior scale.
Key insights
Intrinsic randomness in GP posterior sampling provides differential privacy, critically dependent on effective ridge regularization.
Principles
- Intrinsic model randomness can inhibit data inference.
- Effective ridge regularization is essential for GP privacy.
- Posterior scale alone is insufficient for privacy.
Method
The method involves deriving explicit Rényi-DP bounds for GP posterior sample-path release, separating posterior-mean and data-dependent posterior-covariance leakage, and validating with membership-inference attacks and utility experiments.
In practice
- Use effective ridge regularization for GP privacy.
- Consider adding calibrated GP noise for stronger DP.
- Evaluate privacy-utility tradeoffs in noisy observation regimes.
Topics
- Differential Privacy
- Gaussian Processes
- Rényi-DP Bounds
- Ridge Regularization
- Membership Inference Attacks
- Excursion Set Estimation
Code references
Best for: Research Scientist, AI Scientist, AI Security Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by stat.ML updates on arXiv.org.