Multiclass versus Binary Differentially Private PAC Learning


Mark Bun, Marco Gaboardi, and Satchit Sivakumar. 7/2021. “Multiclass versus Binary Differentially Private PAC Learning.” In Advances in Neural Information Processing Systems 34 (NeurIPS 2021). Publisher's Version
ARXIV.pdf778 KB


We show a generic reduction from multiclass differentially private PAC learning to binary private PAC learning. We apply this transformation to a recently proposed binary private PAC learner to obtain a private multiclass learner with sample complexity that has a polynomial dependence on the multiclass Littlestone dimension and a poly-logarithmic dependence on the number of classes. This yields a doubly exponential improvement in the dependence on both parameters over learners from previous work. Our proof extends the notion of Ψ-dimension defined in work of Ben-David et al. [5] to the online setting and explores its general properties.
Last updated on 09/23/2022