@inproceedings{228c7e43faf64bd8815500618354657c,
title = "DP-Finder: Finding differential privacy violations by sampling and optimization",
abstract = "We present DP-Finder, a novel approach and system that automatically derives lower bounds on the differential privacy enforced by algorithms. Lower bounds are practically useful as they can show tightness of existing upper bounds or even identify incorrect upper bounds. Computing a lower bound involves searching for a counterexample, defined by two neighboring inputs and a set of outputs, that identifies a large privacy violation. This is an inherently hard problem as finding such a counterexample involves inspecting a large (usually infinite) and sparse search space. To address this challenge, DP-Finder relies on two key insights. First, we introduce an effective and precise correlated sampling method to estimate the privacy violation of a counterexample. Second, we show how to obtain a differentiable version of the problem, enabling us to phrase the search task as an optimization objective to be maximized with state-of-the-art numerical optimizers. This allows us to systematically search for large privacy violations. Our experimental results indicate that DP-Finder is effective in computing differential privacy lower bounds for a number of randomized algorithms. For instance, it finds tight lower bounds in algorithms that obfuscate their input in a non-trivial fashion.",
keywords = "Differential privacy, Lower bounds, Optimization, Sampling",
author = "Benjamin Bichsel and Timon Gehr and Dana Drachsler-Cohen and Petar Tsankov and Martin Vechev",
note = "Publisher Copyright: {\textcopyright} 2018 Copyright held by the owner/author(s).; 25th ACM Conference on Computer and Communications Security, CCS 2018 ; Conference date: 15-10-2018",
year = "2018",
month = oct,
day = "15",
doi = "https://doi.org/10.1145/3243734.3243863",
language = "الإنجليزيّة",
series = "Proceedings of the ACM Conference on Computer and Communications Security",
pages = "508--524",
booktitle = "CCS 2018 - Proceedings of the 2018 ACM SIGSAC Conference on Computer and Communications Security",
}