arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2109.09078cs.CRcs.DB
收藏

充分利用差分隐私中的并行组合

Making the Most of Parallel Composition in Differential Privacy

Josh Smith, Hassan Jameel Asghar, Gianpaolo Gioiosa, Sirine Mrabet, Serge Gaspers, Paul Tyler

摘要:

我们表明,“最佳”使用的并行组合定理对应于找到的最大子集的查询,“重叠”的数据域,我们称之为\emph{maximum overlap}的查询量的大小。以前已经表明,这个问题的某个实例,制定在确定查询的敏感性方面,是NP-难的,但也有可能使用图论算法,如找到最大团,近似查询敏感性。在本文中,我们考虑了上述实例的一个重要概括,它包括更广泛的差分私有机制和更广泛的查询类。我们表明,对于一类特定的谓词查询,确定它们是否是不相交的,可以在时间多项式中的属性的数量。对于这个类,我们表明,最大重叠问题仍然是NP难的查询的数量的函数。然而,我们表明,有效的近似解决方案存在的最大重叠的团和色数确定的查询的某个图形。与色数的联系使我们能够使用更有效的近似算法,这对于团数来说是不可能的,因为它可能低估了隐私预算。我们的方法被定义在$f$ -差分隐私,其中包括标准的纯差分隐私和高斯差分隐私的一般设置。证明了$f$ -差分隐私的并行合成定理。我们评估了我们在合成和真实世界查询数据集上的方法。我们表明,该方法可以扩展到大的域大小(高达$10^{20000}$),它的应用程序可以减少噪音添加到查询答案高达60%。

英文摘要:

We show that the `optimal' use of the parallel composition theorem corresponds to finding the size of the largest subset of queries that `overlap' on the data domain, a quantity we call the \emph{maximum overlap} of the queries. It has previously been shown that a certain instance of this problem, formulated in terms of determining the sensitivity of the queries, is NP-hard, but also that it is possible to use graph-theoretic algorithms, such as finding the maximum clique, to approximate query sensitivity. In this paper, we consider a significant generalization of the aforementioned instance which encompasses both a wider range of differentially private mechanisms and a broader class of queries. We show that for a particular class of predicate queries, determining if they are disjoint can be done in time polynomial in the number of attributes. For this class, we show that the maximum overlap problem remains NP-hard as a function of the number of queries. However, we show that efficient approximate solutions exist by relating maximum overlap to the clique and chromatic numbers of a certain graph determined by the queries. The link to chromatic number allows us to use more efficient approximate algorithms, which cannot be done for the clique number as it may underestimate the privacy budget. Our approach is defined in the general setting of $f$-differential privacy, which subsumes standard pure differential privacy and Gaussian differential privacy. We prove the parallel composition theorem for $f$-differential privacy. We evaluate our approach on synthetic and real-world data sets of queries. We show that the approach can scale to large domain sizes (up to $10^{20000}$), and that its application can reduce the noise added to query answers by up to 60\%.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑