P2NIA: Privacy-Preserving Non-Iterative Auditing
Jade Garcia Bourrée, Hadrien Lautraite, Sébastien Gambs, Gilles Tredan, Erwan Le Merrer, Benoît Rottembourg
TL;DR
This work tackles the problem of reliably auditing fairness in high-risk AI under black-box constraints where the platform's data distribution is hidden and privacy concerns limit API access. It introduces P2NIA, a privacy-preserving, non-iterative collaborative auditing scheme in which the platform releases a differentially-private synthetic or anonymized audit dataset to enable unbiased evaluation by the auditor. The authors show that population bias can bias black-box fairness estimates and demonstrate, on the Adult and Folktables datasets, that P2NIA achieves accurate estimates for Demographic Parity, Equalized Odds, and Equality of Opportunity under controllable $ \epsilon$-differential privacy budgets. The approach reduces auditing friction for platforms while improving audit validity, suggesting a practical path for privacy-aware governance; future work includes exploring grey-box extensions.
Abstract
The emergence of AI legislation has increased the need to assess the ethical compliance of high-risk AI systems. Traditional auditing methods rely on platforms' application programming interfaces (APIs), where responses to queries are examined through the lens of fairness requirements. However, such approaches put a significant burden on platforms, as they are forced to maintain APIs while ensuring privacy, facing the possibility of data leaks. This lack of proper collaboration between the two parties, in turn, causes a significant challenge to the auditor, who is subject to estimation bias as they are unaware of the data distribution of the platform. To address these two issues, we present P2NIA, a novel auditing scheme that proposes a mutually beneficial collaboration for both the auditor and the platform. Extensive experiments demonstrate P2NIA's effectiveness in addressing both issues. In summary, our work introduces a privacy-preserving and non-iterative audit scheme that enhances fairness assessments using synthetic or local data, avoiding the challenges associated with traditional API-based audits.
