Privacy-preserving Stochastic Gradual Learning
This addresses privacy concerns in large-scale sensitive data processing for machine learning applications, though it appears incremental as it builds on existing private sampling and curriculum learning methods.
The paper tackles the problem of privacy leakage in stochastic optimization by introducing PRESTIGE, which combines private sampling with curriculum learning to maintain robustness while preserving privacy. Empirical results on six datasets show it achieves a good tradeoff between privacy preservation and robustness over baselines.
It is challenging for stochastic optimizations to handle large-scale sensitive data safely. Recently, Duchi et al. proposed private sampling strategy to solve privacy leakage in stochastic optimizations. However, this strategy leads to robustness degeneration, since this strategy is equal to the noise injection on each gradient, which adversely affects updates of the primal variable. To address this challenge, we introduce a robust stochastic optimization under the framework of local privacy, which is called Privacy-pREserving StochasTIc Gradual lEarning (PRESTIGE). PRESTIGE bridges private updates of the primal variable (by private sampling) with the gradual curriculum learning (CL). Specifically, the noise injection leads to the issue of label noise, but the robust learning process of CL can combat with label noise. Thus, PRESTIGE yields "private but robust" updates of the primal variable on the private curriculum, namely an reordered label sequence provided by CL. In theory, we reveal the convergence rate and maximum complexity of PRESTIGE. Empirical results on six datasets show that, PRESTIGE achieves a good tradeoff between privacy preservation and robustness over baselines.