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arXiv · 2308.11110

A novel analysis of utility in privacy pipelines, using Kronecker products and quantitative information flow

Mário S. Alvim·Natasha Fernandes·Annabelle McIver·Carroll Morgan·Gabriel H. Nunes
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Abstract

We combine Kronecker products, and quantitative information flow, to give a novel formal analysis for the fine-grained verification of utility in complex privacy pipelines. The combination explains a surprising anomaly in the behaviour of utility of privacy-preserving pipelines -- that sometimes a reduction in privacy results also in a decrease in utility. We use the standard measure of utility for Bayesian analysis, introduced by Ghosh at al., to produce tractable and rigorous proofs of the fine-grained statistical behaviour leading to the anomaly. More generally, we offer the prospect of formal-analysis tools for utility that complement extant formal analyses of privacy. We demonstrate our results on a number of common privacy-preserving designs.

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Mário S. Alvim, Natasha Fernandes, Annabelle McIver, Carroll Morgan, Gabriel H. Nunes. 2023-08-22. A novel analysis of utility in privacy pipelines, using Kronecker products and quantitative information flow. https://doi.org/10.1145/3576915.3623081

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