arXiv:2602. 17284v2 Announce Type: replace Abstract: We consider the privacy amplification properties of a sampling scheme in which a user's data isused in $k$ steps chosen randomly and uniformly from a sequence (or set) of $t$ steps.
By Vitaly Feldman, Moshe Shenfeld
The paper introduces a simple mechanism that adds a random number of dummy points to protect batch size information in Differentially Private Stochastic Gradient Descent (DP‑SGD). This approach addresses privacy amplification challenges arising from variable batch sizes and truncation in both centralized and distributed settings. The authors provide a general analysis for Poisson sampling and random allocation, showing that the expected number of dummy points is asymptotically smaller than directly privatizing batch sizes, and demonstrate empirically that their method outperforms recent truncation accounting techniques.
By Vitaly Feldman, Audra McMillan, Kunal Talwar
The paper presents a Gaussian approximation for the privacy loss distribution in differentially private stochastic gradient descent (DP‑SGD) when subsampling is used. It shows that, after truncating rare large losses, the privacy loss behaves like a Gaussian with the same mean and variance, up to a small shift that grows only logarithmically with the error tolerance. This leads to tighter variance‑based bounds for subsampled mechanisms, improving upon previous Renyi‑divergence analyses and explaining the effectiveness of the connect‑the‑dots method for random allocation sampling.
By Vitaly Feldman, Moshe Shenfeld
arXiv:2605. 06259v3 Announce Type: replace Abstract: Within the $f$-DP framework, we derive a tight analysis of the trade-off function for Differentially Private Stochastic Gradient Descent (DP-SGD) with subsampling based on random allocation in which each sample is independently assigned to exactly one of $M$ minibatches per epoch, each minibatch corresponding to one of the $M$ SGD rounds within a single epoch.
By Marten van Dijk, Murat Bilgehan Ertan
arXiv:2609. 22783v1 Announce Type: new Abstract: We study differentially private covariance estimation in operator norm for mean-zero sub-Gaussian distributions with unknown covariance support and at most $k$ nonzero entries per row.
By Zihan Zhang
We study learning a discrete distribution under person-level differential privacy in the batched setting. Given $n$ users, each contributing $m$ i.