titleExploring The Empirical Privacy Landscape of Synthetic Data
authorsZihao Zhao, Avi Schwarzschild, Casey Meehan, Katherine Lee, Zhili Feng, Dylan Sam
date2026-10-15
venuearXiv (preprint, not peer reviewed)
idarXiv:2610.22659
upvotes3 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf
abstractMethods for training language models on sensitive data differ in how they balance capability gains against the risk of leaking private information. In this paper, we present a controlled comparison of data-level and training-level interventions for navigating the capability-privacy tradeoff on synthetic medical records with canaries to probe for leakage. Direct finetuning performs best on capability metrics but leads to the most privacy leakage, while DP-SGD reduces leakage at substantial cost to capabilities. Generating synthetic data from these records offers a more favorable balance, particularly when guided by a uniqueness-aware instruction to replace private details. Relative to naive paraphrasing, privacy-aware rewriting improves privacy protection across a variety of different rewriting models. We also find that more capable rewriting models generally reduce the risks of downstream privacy leakage, although held-out fit does not improve monotonically and increased test-time compute yields inconsistent gains. Overall, these results highlight privacy-aware rewriting as a promising direction for achieving a more favorable trade-off between capabilities and empirical privacy compared to other training-level methods, and our evaluation framework supports comparisons of future models and methods.

cite

@misc{zhao2026exploring,
  title={Exploring The Empirical Privacy Landscape of Synthetic Data},
  author={Zihao Zhao and Avi Schwarzschild and Casey Meehan and Katherine Lee and Zhili Feng and Dylan Sam},
  year={2026},
  eprint={2610.22659},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2610.22659}
}