Accuracy Improvement in Differentially Private Logistic Regression: A Pre-training Approach

Machine learning (ML) models can memorize training datasets. As a result, training ML models on private datasets can lead to the violation of individuals’ privacy. Differential privacy (DP) is a rigorous privacy notion to preserve the privacy of the underlying training datasets. However, training ML models in a DP framework usually degrades the accuracy of ML models. This paper aims to increase the accuracy of a DP logistic regression (LR) via a pre-training module. In more detail, we initially pre-train our LR model on a public training dataset without any privacy concern. Then, we fine-tune our DP-LR model with the private dataset. In the numerical results, we show that adding a pre-training module significantly improves the accuracy of the DP-LR model.