On the Optimal Regret of Locally Private Linear Contextual Bandit

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Li, Jiachun, Simchi-Levi, David, Wang, Yining
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917639445544960
author Li, Jiachun
Simchi-Levi, David
Wang, Yining
author_facet Li, Jiachun
Simchi-Levi, David
Wang, Yining
contents Contextual bandit with linear reward functions is among one of the most extensively studied models in bandit and online learning research. Recently, there has been increasing interest in designing \emph{locally private} linear contextual bandit algorithms, where sensitive information contained in contexts and rewards is protected against leakage to the general public. While the classical linear contextual bandit algorithm admits cumulative regret upper bounds of $\tilde O(\sqrt{T})$ via multiple alternative methods, it has remained open whether such regret bounds are attainable in the presence of local privacy constraints, with the state-of-the-art result being $\tilde O(T^{3/4})$. In this paper, we show that it is indeed possible to achieve an $\tilde O(\sqrt{T})$ regret upper bound for locally private linear contextual bandit. Our solution relies on several new algorithmic and analytical ideas, such as the analysis of mean absolute deviation errors and layered principal component regression in order to achieve small mean absolute deviation errors.
format Preprint
id arxiv_https___arxiv_org_abs_2404_09413
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle On the Optimal Regret of Locally Private Linear Contextual Bandit
Li, Jiachun
Simchi-Levi, David
Wang, Yining
Machine Learning
Cryptography and Security
Contextual bandit with linear reward functions is among one of the most extensively studied models in bandit and online learning research. Recently, there has been increasing interest in designing \emph{locally private} linear contextual bandit algorithms, where sensitive information contained in contexts and rewards is protected against leakage to the general public. While the classical linear contextual bandit algorithm admits cumulative regret upper bounds of $\tilde O(\sqrt{T})$ via multiple alternative methods, it has remained open whether such regret bounds are attainable in the presence of local privacy constraints, with the state-of-the-art result being $\tilde O(T^{3/4})$. In this paper, we show that it is indeed possible to achieve an $\tilde O(\sqrt{T})$ regret upper bound for locally private linear contextual bandit. Our solution relies on several new algorithmic and analytical ideas, such as the analysis of mean absolute deviation errors and layered principal component regression in order to achieve small mean absolute deviation errors.
title On the Optimal Regret of Locally Private Linear Contextual Bandit
topic Machine Learning
Cryptography and Security
url https://arxiv.org/abs/2404.09413