Abstract: Given a trained model and a data sample, membership-inference (MI) attacks predict whether the sample was in the model's training set. A common countermeasure against MI attacks is to utilize differential privacy (DP) during model training to mask the presence of individual examples. While this use of DP is a principled approach to limit the efficacy of MI attacks, there is a gap between the bounds provided by DP and the empirical performance of MI attacks. In this paper, we derive bounds for the advantage of an adversary mounting a MI attack, and demonstrate tightness for the widely-used Gaussian mechanism.

Bio: Alexandre Sablayrolles is a Research Scientist at Meta AI in Paris, working on the privacy and security of machine learning systems. He received his PhD from Université Grenoble Alpes in 2020, following a joint CIFRE program with Facebook AI. Prior to that, he completed his Master's degree in Data Science at NYU, and received a B.S. and M.S. in Applied Mathematics and Computer Science from École Polytechnique. Alexandre's research interests include privacy and security, computer vision, and applications of deep learning.