🤖 AI Summary
This work addresses the challenge of preserving high-order variable correlations in synthetic tabular data under differential privacy. The authors propose Tab-PE, the first algorithm to extend the Private Evolution framework to tabular data generation. Tab-PE introduces low-overhead heuristic evolutionary operators that efficiently optimize candidate datasets within differential privacy constraints, combined with a private scoring and selection mechanism to simultaneously capture complex correlations and ensure scalability. Experimental results demonstrate that Tab-PE significantly outperforms existing methods on both real-world and synthetic datasets, achieving up to a 10% improvement in classification accuracy over the AIM baseline while running 28 times faster.
📝 Abstract
This paper investigates the problem of generating synthetic tabular data with differential privacy (DP) guarantees, enabling data sharing in sensitive domains. Despite extensive study, state-of-the-art methods often focus on minimizing low-order marginal query errors and overlook the challenges posed by high-order correlations. To address this gap, we extend the Private Evolution (PE) framework, originally developed for DP-compliant image and text synthesis, to tabular data. We introduce Tab-PE -- an algorithm for synthetic tabular data generation under DP constraints. Tab-PE iteratively improves a candidate dataset via an evolutionary process that leverages tabular-specialized operators to produce variations, privately scores them, and selects the highest-quality samples to retain and propagate. In contrast to the original PE, which relies on large foundation models, Tab-PE employs heuristic operators with significantly lower computational costs, making PE more practical and scalable for tabular data. Through extensive experiments on real-world and simulation datasets, we demonstrate that Tab-PE substantially outperforms prior baselines on datasets exhibiting high-order correlations. Compared to the best baseline -- AIM, Tab-PE improves classification accuracy by up to 10% while running 28 times faster.