论文标题
所有人的隐私:对差异隐私的脆弱性差异针对会员推理攻击
Privacy for All: Demystify Vulnerability Disparity of Differential Privacy against Membership Inference Attack
论文作者
论文摘要
机器学习算法(应用于敏感数据)对隐私构成潜在威胁。越来越多的先前工作表明,会员推理攻击(MIA)可以向攻击者披露培训数据中的特定私人信息。同时,机器学习的算法公平越来越引起了学术界和行业的关注。算法公平可确保机器学习模型不会区分特定的人群(例如黑人和女性)。鉴于MIA确实是一种学习模型,如果MIA``公平地''同样对待所有群体,就会引起严重的关注。换句话说,特定群体是否比其他群体更容易对MIA。本文研究了MIA及其防御措施中的算法公平问题。首先,为了进行公平评估,它正式化了脆弱性差异(VD)的符号,以量化不同人口组的MIA治疗差异。其次,它评估了四个现实世界数据集上的VD,并表明VD确实存在于这些数据集中。第三,它研究了差异隐私作为MIA的防御机制的影响。结果表明,尽管DP在VD上带来了重大变化,但不能完全消除VD。因此,第四,它设计了一种名为Fairpick的新缓解算法,以减少VD。一组广泛的实验结果表明,Fairpick可以有效地减少有或没有DP部署的VD。
Machine learning algorithms, when applied to sensitive data, pose a potential threat to privacy. A growing body of prior work has demonstrated that membership inference attack (MIA) can disclose specific private information in the training data to an attacker. Meanwhile, the algorithmic fairness of machine learning has increasingly caught attention from both academia and industry. Algorithmic fairness ensures that the machine learning models do not discriminate a particular demographic group of individuals (e.g., black and female people). Given that MIA is indeed a learning model, it raises a serious concern if MIA ``fairly'' treats all groups of individuals equally. In other words, whether a particular group is more vulnerable against MIA than the other groups. This paper examines the algorithmic fairness issue in the context of MIA and its defenses. First, for fairness evaluation, it formalizes the notation of vulnerability disparity (VD) to quantify the difference of MIA treatment on different demographic groups. Second, it evaluates VD on four real-world datasets, and shows that VD indeed exists in these datasets. Third, it examines the impacts of differential privacy, as a defense mechanism of MIA, on VD. The results show that although DP brings significant change on VD, it cannot eliminate VD completely. Therefore, fourth, it designs a new mitigation algorithm named FAIRPICK to reduce VD. An extensive set of experimental results demonstrate that FAIRPICK can effectively reduce VD for both with and without the DP deployment.