From Theory to Comprehension: A Comparative Study of Differential Privacy and $k$-Anonymity
Saskia Nuñez von Voigt, Luise Mehner, Florian Tschorsch
TL;DR
This study addresses how users comprehend the privacy guarantees of ε-differential privacy, comparing three explanatory models (DEF, RISK, RRT) against a baseline for k-anonymity. Using a drug-survey scenario, the authors evaluate subjective and objective comprehension, revealing that RRT most effectively enhances perceived understanding of differential privacy, while k-anonymity is generally more comprehensible overall. Objective measures remain highest for k-anonymity, with RISK and RRT improving differential privacy understanding but not matching the baseline simplicity of k-anonymity. The findings inform how to communicate privacy guarantees to end users and suggest that randomized-response-based explanations are promising for improving DP comprehension in practice.
Abstract
The notion of $\varepsilon$-differential privacy is a widely used concept of providing quantifiable privacy to individuals. However, it is unclear how to explain the level of privacy protection provided by a differential privacy mechanism with a set $\varepsilon$. In this study, we focus on users' comprehension of the privacy protection provided by a differential privacy mechanism. To do so, we study three variants of explaining the privacy protection provided by differential privacy: (1) the original mathematical definition; (2) $\varepsilon$ translated into a specific privacy risk; and (3) an explanation using the randomized response technique. We compare users' comprehension of privacy protection employing these explanatory models with their comprehension of privacy protection of $k$-anonymity as baseline comprehensibility. Our findings suggest that participants' comprehension of differential privacy protection is enhanced by the privacy risk model and the randomized response-based model. Moreover, our results confirm our intuition that privacy protection provided by $k$-anonymity is more comprehensible.
