A Learning-based Declarative Privacy-Preserving Framework for Federated Data Management

It is challenging to select the right privacy-preserving mechanism for federated query processing over multiple private data silos. There exist numerous privacy-preserving mechanisms, such as secure multi-party computing (SMC), approximate query processing with differential privacy (DP), combined SMC and DP, DP-based data obfuscation, and federated learning. These mechanisms make different trade-offs among accuracy, privacy, execution efficiency, and storage efficiency. In this work, we first introduce a new privacy-preserving technique that uses a deep learning model trained using the Differentially-Private Stochastic Gradient Descent (DP-SGD) algorithm to replace portions of actual data to answer a query. We then demonstrate a novel declarative privacy-preserving workflow that allows users to specify "what private information to protect" rather than "how to protect". Under the hood, the system relies on a cost model to automatically choose privacy-preserving mechanisms as well as hyper-parameters. At the same time, the proposed workflow also allows human experts to review and tune the selected privacy-preserving mechanism for audit/compliance, and optimization purposes.