Initial Exploration of Zero-Shot Privacy Utility Tradeoffs in Tabular Data Using GPT-4
Bishwas Mandal, George Amariucai, Shuangqing Wei
TL;DR
This work explores privacy-utility tradeoffs in tabular data using GPT-4 as a zero-shot sanitization tool. By converting tabular rows to text and appending sanitization instructions in prompts, the authors create a sanitizing function via$f(.)=g(p(.))$, yielding sanitized data $\,\hat{D}$ that preserves utility features $D_U$ while obscuring private features $D_P$. Across the UCI Adult dataset with two task configurations, GPT-4-based prompts achieve privacy protection comparable to adversarial baselines and, in some configurations, even superior utility retention, though fairness metrics are not uniformly satisfied. The study highlights the potential of LLMs for privacy-preserving data sharing without additional training, while acknowledging limitations in fairness and pointing to future improvements with advancing models.
Abstract
We investigate the application of large language models (LLMs), specifically GPT-4, to scenarios involving the tradeoff between privacy and utility in tabular data. Our approach entails prompting GPT-4 by transforming tabular data points into textual format, followed by the inclusion of precise sanitization instructions in a zero-shot manner. The primary objective is to sanitize the tabular data in such a way that it hinders existing machine learning models from accurately inferring private features while allowing models to accurately infer utility-related attributes. We explore various sanitization instructions. Notably, we discover that this relatively simple approach yields performance comparable to more complex adversarial optimization methods used for managing privacy-utility tradeoffs. Furthermore, while the prompts successfully obscure private features from the detection capabilities of existing machine learning models, we observe that this obscuration alone does not necessarily meet a range of fairness metrics. Nevertheless, our research indicates the potential effectiveness of LLMs in adhering to these fairness metrics, with some of our experimental results aligning with those achieved by well-established adversarial optimization techniques.
