arXiv Machine Learning

Characterizing Privacy-Audit Alignment in Behavioral Audit of Machine Unlearning

The paper investigates the privacy risks inherent in auditing machine unlearning (MU) when the audit relies only on querying the model for behavioral signals. It shows that such generic audit schemes inevitably leak information about the retained data set, providing a geometric transfer theorem that bounds the distinguishability of retained set membership based on audit accuracy. The study also analyzes how the unlearned set, target sample, and query protocol influence the privacy‑audit transfer coefficient, with empirical evidence from both convex and non‑convex models supporting the theoretical findings.

arXiv Machine Learning
Jun 15

Let's Ask Gauss: Improved One-Run Privacy Auditing

arXiv:2606. 12733v2 Announce Type: replace Abstract: Privacy auditing provides an important safeguard by estimating the actual information leaked by a model, thus ensuring that theoretical privacy guarantees hold in practice.

By Adya Agrawal, Yu Wei, Jaspal Singh, Malik Magdon-Ismail, Vassilis Zikas
arXiv Machine Learning
Sep 23

Optimizing Canaries for Privacy Auditing with Metagradient Descent

The paper investigates black-box privacy auditing for differentially private learning algorithms, focusing on DP‑SGD. It introduces a method that optimizes the auditor’s canary set using metagradient descent, improving empirical lower bounds on privacy parameters compared to prior canary designs. The approach is shown to be DP‑SGD agnostic and efficient, with optimized canaries for small models remaining effective for larger DP‑SGD models.

By Matteo Boglioni, Terrance Liu, Andrew Ilyas, Zhiwei Steven Wu
arXiv AI
Oct 21

Reliable Estimation of Differential Privacy under Selection Bias

The paper addresses a flaw in differential privacy audits where selection bias in Membership Inference Attacks leads to overestimated lower bounds on privacy leakage. By applying statistical correction methods, the authors demonstrate that uncorrected audits can violate theoretical privacy guarantees up to four times more often than claimed, while corrected audits maintain valid bounds at the nominal confidence level.

By Valentin Dorseuil (DI-ENS), Meenatchi Sundaram Muthu Selva Annamalai (UCL), Jamal Atif (CMAP), Olivier Capp\'e (DI-ENS), Nicolas Papernot (Inria)