Notes on Information-Theoretic Privacy

TL;DR

This paper explores the fundamental tradeoff between privacy and utility using mutual information, providing complete characterizations for binary data and introducing a new measure of private information.

Contribution

It fully characterizes the privacy-utility tradeoff for binary data under perfect privacy and introduces a new metric linking private information to this tradeoff.

Findings

Complete characterization of privacy-utility tradeoff for binary data

Upper bounds for privacy leakage scenarios

Introduction of a new private information measure

Abstract

We investigate the tradeoff between privacy and utility in a situation where both privacy and utility are measured in terms of mutual information. For the binary case, we fully characterize this tradeoff in case of perfect privacy and also give an upper-bound for the case where some privacy leakage is allowed. We then introduce a new quantity which quantifies the amount of private information contained in the observable data and then connect it to the optimal tradeoff between privacy and utility.