Privacy Amplification of Iterative Algorithms via Contraction Coefficients

Autor: Flavio P. Calmon, Mario Diaz, Shahab Asoodeh
Rok vydání: 2020
Předmět:
Zdroj: ISIT
DOI: 10.48550/arxiv.2001.06546
Popis: We investigate the framework of privacy amplification by iteration, recently proposed by Feldman et al., from an information-theoretic lens. We demonstrate that differential privacy guarantees of iterative mappings can be determined by a direct application of contraction coefficients derived from strong data processing inequalities for $f$-divergences. In particular, by generalizing the Dobrushin's contraction coefficient for total variation distance to an $f$-divergence known as $E_{\gamma}$-divergence, we derive tighter bounds on the differential privacy parameters of the projected noisy stochastic gradient descent algorithm with hidden intermediate updates.
Comment: Submitted for publication
Databáze: OpenAIRE