Poster
Faster Differentially Private Top-$k$ Selection: A Joint Exponential Mechanism with Pruning
Hao WU · Hanwen Zhang
West Ballroom A-D #6305
[
Abstract
]
Thu 12 Dec 4:30 p.m. PST
— 7:30 p.m. PST
Abstract:
We study the differentially private top-$k$ selection problem, aiming to identify a sequence of $k$ items with approximately the highest scores from $d$ items. Recent work by Gillenwater et al. (2022) employs a direct sampling approach from the vast collection of $O(d^k)$ possible length-$k$ sequences, showing superior empirical accuracy compared to previous pure or approximate differentially private methods. Their algorithm has a time and space complexity of $\tilde{O}(dk)$. In this paper, we present an improved algorithm that achieves time and space complexity of $\tilde{O}(d + k^2)$.Experimental results show that our algorithm runs orders of magnitude faster than their approach, while achieving similar empirical accuracy.
Live content is unavailable. Log in and register to view live content