arXiv Machine Learning

Fast Privacy Loss Accounting for Random Allocation via Multiscale FFT

arXiv:2610. 42117v1 Announce Type: new Abstract: In the random allocation sampling scheme each user's data is used in $k$ steps chosen randomly and uniformly from a sequence of $t$ steps.

arXiv Machine Learning
4d ago

Counting on Dummies: Privacy Amplification with Observable Counts and Truncated Batches

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
arXiv Machine Learning
Oct 28

Gaussian Approximation for Composition and Subsampling of Differentially Private Algorithms

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 Machine Learning
Oct 5

Trade-off Functions for DP-SGD with Subsampling based on Random Allocation: Tight Upper and Lower Bounds

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