
differential-privacy-e2fa3c10·8 events·first seen Aliases: Differential Privacy
A new arXiv preprint introduces 'privacy via predictability,' a framework that measures privacy leakage as the incremental gain in an attacker's ability to predict sensitive information after observing an algorithm's output, conditioned on the attacker's prior knowledge. The authors show predictability and differential privacy are generally incomparable, but that predictability implies mutual-information DP in worst-case regimes. They develop a generalized method of moments framework for asymptotic analysis and derive a predictability-calibrated output perturbation scheme for empirical risk minimization. The work positions predictability as a complementary, finer-grained alternative to DP for settings where attacker knowledge and query families can be specified.
A new arXiv preprint introduces a model-agnostic empirical framework for auditing synthetic data generated by LLMs and generative AI systems for privacy leakage. The framework distinguishes 'true disclosures' (direct reproduction of user data) from 'phantom disclosures' (incidental generation), using held-out control sets and statistical hypothesis testing without requiring model access, canary insertion, or shadow model training. It functions as a membership inference attack and provides empirical lower bounds on privacy leakage that are tighter than prior data-based auditing methods. The approach is computationally lightweight and applicable to any synthetic data generation mechanism.
This paper identifies a novel Privacy Inference Attack against heterogeneous differential privacy federated learning (HDP-FL) systems, where an honest-but-curious server exploits epsilon-aware aggregation and gradient denoising to infer client data distributions and link updates across rounds. To counter this, the authors propose IntraShuffler, a middleware framework that groups clients into privacy-compatible buckets and performs parameter-level shuffling within buckets, preserving epsilon-aware aggregation while disrupting persistent gradient structure. Experiments on four datasets show IntraShuffler reduces gradient recoverability by over 60% and drops surrogate inference accuracy from 0.78 to 0.33 with minimal utility loss.
This paper develops a perturbation theory for Spherical Hellinger-Kantorovich (SHK) gradient flows, which couple transport and reaction dynamics and coincide with birth-death Langevin dynamics. The authors derive dimension-free bounds on log-likelihood ratios and Rényi/KL divergences when two potentials differ, quantifying how perturbations propagate over time. These results are applied to differential privacy: the likelihood-ratio control yields explicit Pure-DP guarantees for SHK-based samplers implementing the exponential mechanism, while KL bounds provide Approximate-DP certificates. A utility bound is also derived that separates intrinsic exponential-mechanism suboptimality from finite-time sampling error.
CHRONOS is a three-layer multi-agent architecture addressing temporal degradation in knowledge-graph data marketplaces, combining neural-ODE-based shortcut decay, changepoint-conditioned Shapley pricing, and EXP3-IX-driven differential privacy budget management. The system achieves 0.937 recall@10, 2.74 QPS, and 161ms latency under a total epsilon of 4.25 (delta=1e-6) using zCDP composition across four benchmarks. A key limitation noted is that at this privacy level, released valuations remain noise-dominated, with utility primarily derived from public index routing. The work provides formal guarantees including per-query recall-loss bounds and finite-sample Shapley error bounds under distribution shift.
OpenAI published research on semi-supervised knowledge transfer techniques for training deep learning models on private data, an early contribution to privacy-preserving machine learning. The work addresses how to leverage private training data without exposing sensitive information, using knowledge distillation-style approaches. This is a 2016 archival post surfaced from OpenAI's blog.
DeepMind introduces VaultGemma, a large language model trained from scratch using differential privacy (DP), claiming it as the most capable DP-trained model to date. The announcement positions VaultGemma as a significant advance in privacy-preserving AI, combining strong utility with formal privacy guarantees. The blog post is brief and likely precedes a more detailed technical disclosure.
This paper characterizes how differential privacy affects the statistical complexity of CVaR (Conditional Value at Risk) optimization, showing that the effective sample size governing private tail-risk learning is εnτ rather than n, where τ is the tail mass. Complete minimax rates are derived for scalar estimation and finite classes under pure DP, with lower bounds extending to approximate DP. For convex Lipschitz learning, the CVaR-specific privacy cost necessarily scales as 1/(εnτ), with dimension dependence inherited from private stochastic convex optimization. The results reduce private CVaR learning to private learning on Θ(nτ) tail records as the canonical hard subproblem.