Subset-Based Instance Optimality in Private Estimation

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Dick, Travis, Kulesza, Alex, Sun, Ziteng, Suresh, Ananda Theertha
Format: Preprint
Publié: 2023
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866913367349788672
author Dick, Travis
Kulesza, Alex
Sun, Ziteng
Suresh, Ananda Theertha
author_facet Dick, Travis
Kulesza, Alex
Sun, Ziteng
Suresh, Ananda Theertha
contents We propose a new definition of instance optimality for differentially private estimation algorithms. Our definition requires an optimal algorithm to compete, simultaneously for every dataset $D$, with the best private benchmark algorithm that (a) knows $D$ in advance and (b) is evaluated by its worst-case performance on large subsets of $D$. That is, the benchmark algorithm need not perform well when potentially extreme points are added to $D$; it only has to handle the removal of a small number of real data points that already exist. This makes our benchmark significantly stronger than those proposed in prior work. We nevertheless show, for real-valued datasets, how to construct private algorithms that achieve our notion of instance optimality when estimating a broad class of dataset properties, including means, quantiles, and $\ell_p$-norm minimizers. For means in particular, we provide a detailed analysis and show that our algorithm simultaneously matches or exceeds the asymptotic performance of existing algorithms under a range of distributional assumptions.
format Preprint
id arxiv_https___arxiv_org_abs_2303_01262
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Subset-Based Instance Optimality in Private Estimation
Dick, Travis
Kulesza, Alex
Sun, Ziteng
Suresh, Ananda Theertha
Machine Learning
Cryptography and Security
Information Theory
We propose a new definition of instance optimality for differentially private estimation algorithms. Our definition requires an optimal algorithm to compete, simultaneously for every dataset $D$, with the best private benchmark algorithm that (a) knows $D$ in advance and (b) is evaluated by its worst-case performance on large subsets of $D$. That is, the benchmark algorithm need not perform well when potentially extreme points are added to $D$; it only has to handle the removal of a small number of real data points that already exist. This makes our benchmark significantly stronger than those proposed in prior work. We nevertheless show, for real-valued datasets, how to construct private algorithms that achieve our notion of instance optimality when estimating a broad class of dataset properties, including means, quantiles, and $\ell_p$-norm minimizers. For means in particular, we provide a detailed analysis and show that our algorithm simultaneously matches or exceeds the asymptotic performance of existing algorithms under a range of distributional assumptions.
title Subset-Based Instance Optimality in Private Estimation
topic Machine Learning
Cryptography and Security
Information Theory
url https://arxiv.org/abs/2303.01262