Optimal Variance and Covariance Estimation under Differential Privacy in the Add-Remove Model and Beyond

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Takakura, Shokichi, Liew, Seng Pei, Hasegawa, Satoshi
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866908521053814784
author Takakura, Shokichi
Liew, Seng Pei
Hasegawa, Satoshi
author_facet Takakura, Shokichi
Liew, Seng Pei
Hasegawa, Satoshi
contents In this paper, we study the problem of estimating the variance and covariance of datasets under differential privacy in the add-remove model. While estimation in the swap model has been extensively studied in the literature, the add-remove model remains less explored and more challenging, as the dataset size must also be kept private. To address this issue, we develop efficient mechanisms for variance and covariance estimation based on the \emph{Bézier mechanism}, a novel moment-release framework that leverages Bernstein bases. We prove that our proposed mechanisms are minimax optimal in the high-privacy regime by establishing new minimax lower bounds. Moreover, beyond worst-case scenarios, we analyze instance-wise utility and show that the Bézier-based estimator consistently achieves better utility compared to alternative mechanisms. Finally, we demonstrate the effectiveness of the Bézier mechanism beyond variance and covariance estimation, showcasing its applicability to other statistical tasks.
format Preprint
id arxiv_https___arxiv_org_abs_2509_04919
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Optimal Variance and Covariance Estimation under Differential Privacy in the Add-Remove Model and Beyond
Takakura, Shokichi
Liew, Seng Pei
Hasegawa, Satoshi
Machine Learning
Data Structures and Algorithms
In this paper, we study the problem of estimating the variance and covariance of datasets under differential privacy in the add-remove model. While estimation in the swap model has been extensively studied in the literature, the add-remove model remains less explored and more challenging, as the dataset size must also be kept private. To address this issue, we develop efficient mechanisms for variance and covariance estimation based on the \emph{Bézier mechanism}, a novel moment-release framework that leverages Bernstein bases. We prove that our proposed mechanisms are minimax optimal in the high-privacy regime by establishing new minimax lower bounds. Moreover, beyond worst-case scenarios, we analyze instance-wise utility and show that the Bézier-based estimator consistently achieves better utility compared to alternative mechanisms. Finally, we demonstrate the effectiveness of the Bézier mechanism beyond variance and covariance estimation, showcasing its applicability to other statistical tasks.
title Optimal Variance and Covariance Estimation under Differential Privacy in the Add-Remove Model and Beyond
topic Machine Learning
Data Structures and Algorithms
url https://arxiv.org/abs/2509.04919