Technology
AGeneral Framework for Auditing Differentially Private Machine Learning
We present a framework to statistically audit the privacy guarantee conferred by a differentially private machine learner in practice. While previous works have taken steps toward evaluating privacy loss through poisoning attacks or membership inference, they have been tailored to specific models or have demonstrated low statistical power. Our work develops a general methodology to empirically evaluate the privacy of differentially private machine learning implementations, combining improved privacy search and verification methods with a toolkit of influence-based poisoning attacks. We demonstrate significantly improved auditing power over previous approaches on a variety of models including logistic regression, Naive Bayes, and random forest. Our method can be used to detect privacy violations due to implementation errors or misuse. When violations are not present, it can aid in understanding the amount of information that can be leaked from a given dataset, algorithm, and privacy specification.
1abed6ee581b9ceb4e2ddf37822c7fcb-Supplemental-Conference.pdf
A.1 Graph-building strategies The graphs were built using the IsayevNN class from the pymatgen [48] package. It implements the commonly used Voronoi tessalation to define neighbors. Two atoms are considered bonded if they share a face in the Voronoi tessalation of the supercell and their distance is less than the sum of the atomic Cordero radii (a measure of the atomic radius) plus a cutoff =0 .5ร . This value of the cutoff was increase compared to [32] to reduce the number of disconnected graphs. We provide statistics for the graphs obtained by the method described in Section 5. A hard cutoff on atomic distances of 6ร is also imposed on atomic distances. Figure 5: Histogram of the number of primitive cell sites per material in the processed Materials Project dataset.
Equivariant Networks for Crystal Structures
Supervised learning with deep models has tremendous potential for applications in materials science. Recently, graph neural networks have been used in this context, drawing direct inspiration from models for molecules. However, materials are typically much more structured than molecules, which is a feature that these models do not leverage. In this work, we introduce a class of models that are equivariant with respect to crystalline symmetry groups. We do this by defining a generalization of the message passing operations that can be used with more general permutation groups, or that can alternatively be seen as defining an expressive convolution operation on the crystal graph. Empirically, these models achieve competitive results with state-of-the-art on property prediction tasks.
proofs of Section 3
Assume |S|= m, for some m>0. Then, corresponding set of incorrectly-labelled examples is of size | S|= m(k 1). Let D S, be any distribution over m (k 1). We show that we can construct a distribution D S S over m k, for which the guarantee in the Lemma holds. First, observe that there must exist a m and b1,...,bm (k 1), such that for all i,j, we have D(i,j) = a(i)bi(j).