Authors: Noga Alon,Roi Livni,Maryanthe Malliaris,Shay Moran
ArXiv: 1806.00949
Document:
PDF
DOI
Abstract URL: http://arxiv.org/abs/1806.00949v3
We show that every approximately differentially private learning algorithm
(possibly improper) for a class $H$ with Littlestone dimension~$d$ requires
$\Omega\bigl(\log^*(d)\bigr)$ examples. As a corollary it follows that the
class of thresholds over $\mathbb{N}$ can not be learned in a private manner;
this resolves open question due to [Bun et al., 2015, Feldman and Xiao, 2015].
We leave as an open question whether every class with a finite Littlestone
dimension can be learned by an approximately differentially private algorithm.