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David Evans

16 accepted papers

2024

Addressing Both Statistical and Causal Gender Fairness in NLP Models

NAACL 2024findings

Statistical fairness stipulates equivalent outcomes for every protected group, whereas causal fairness prescribes that a model makes the same prediction for an individual regardless of their protected characteristics. Counterfactual data augmentation (CDA) is effective for reducing bias in NLP model…

2023

Efficient Privacy-Preserving Stochastic Nonconvex Optimization

UAI 2023poster

While many solutions for privacy-preserving convex empirical risk minimization (ERM) have been developed, privacy-preserving nonconvex ERM remains a challenge. We study nonconvex ERM, which takes the form of minimizing a finite-sum of nonconvex loss functions over a training set. We propose a new di…

Cited by 62SourcePDFScholar
2023

GlucoSynth: Generating Differentially-Private Synthetic Glucose Traces

NeurIPS 2023poster

We focus on the problem of generating high-quality, private synthetic glucose traces, a task generalizable to many other time series sources. Existing methods for time series data synthesis, such as those using Generative Adversarial Networks (GANs), are not able to capture the innate characteristic…

Cited by 4SourcePDFScholar
2023

Manipulating Transfer Learning for Property Inference

CVPR 2023poster

Transfer learning is a popular method for tuning pretrained (upstream) models for different downstream tasks using limited data and computational resources. We study how an adversary with control over an upstream model used in transfer learning can conduct property inference attacks on a victim's tu…

2023

What Distributions are Robust to Indiscriminate Poisoning Attacks for Linear Learners?

NeurIPS 2023poster

We study indiscriminate poisoning for linear learners where an adversary injects a few crafted examples into the training data with the goal of forcing the induced model to incur higher test error. Inspired by the observation that linear learners on some datasets are able to resist the best known a…

Cited by 2SourcePDFScholar
2022

An Empirical Analysis of Memorization in Fine-tuned Autoregressive Language Models

EMNLP 2022main

Large language models are shown to present privacy risks through memorization of training data, andseveral recent works have studied such risks for the pre-training phase. Little attention, however, has been given to the fine-tuning phase and it is not well understood how different fine-tuning metho…

Cited by 88SourcePDFScholar
2022

Balanced Adversarial Training: Balancing Tradeoffs between Fickleness and Obstinacy in NLP Models

EMNLP 2022main

Traditional (fickle) adversarial examples involve finding a small perturbation that does not change an input’s true label but confuses the classifier into outputting a different prediction. Conversely, obstinate adversarial examples occur when an adversary finds a small perturbation that preserves t…

2021

Improved Estimation of Concentration Under $\ell_p$-Norm Distance Metrics Using Half Spaces

ICLR 2021poster

Concentration of measure has been argued to be the fundamental cause of adversarial vulnerability. Mahloujifar et al. (2019) presented an empirical way to measure the concentration of a data distribution using samples, and employed it to find lower bounds on intrinsic robustness for several benchmar…

2021

Model-Targeted Poisoning Attacks with Provable Convergence

ICML 2021spotlight

In a poisoning attack, an adversary who controls a small fraction of the training data attempts to select that data, so a model is induced that misbehaves in a particular way. We consider poisoning attacks against convex machine learning models and propose an efficient poisoning attack designed to i…

2020

Learning Adversarially Robust Representations via Worst-Case Mutual Information Maximization

ICML 2020poster

Training machine learning models that are robust against adversarial inputs poses seemingly insurmountable challenges. To better understand adversarial robustness, we consider the underlying problem of learning robust representations. We develop a notion of representation vulnerability that captures…

2020

Understanding the Intrinsic Robustness of Image Distributions using Conditional Generative Models

AISTATS 2020poster

Starting with Gilmer et al. (2018), several works have demonstrated the inevitability of adversarial examples based on different assumptions about the underlying input probability space. It remains unclear, however, whether these results apply to natural image distributions. In this work, we assume…

2019

Empirically Measuring Concentration: Fundamental Limits on Intrinsic Robustness

NeurIPS 2019spotlight

Many recent works have shown that adversarial examples that fool classifiers can be found by minimally perturbing a normal input. Recent theoretical results, starting with Gilmer et al. (2018b), show that if the inputs are drawn from a concentrated metric probability space, then adversarial examples…

2018

Distributed Learning without Distress: Privacy-Preserving Empirical Risk Minimization

NeurIPS 2018poster

Distributed learning allows a group of independent data owners to collaboratively learn a model over their data sets without exposing their private data. We present a distributed learning approach that combines differential privacy with secure multi-party computation. We explore two popular methods…