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Om Thakkar

14 accepted papers

2023

Measuring Forgetting of Memorized Training Examples

ICLR 2023poster

Machine learning models exhibit two seemingly contradictory phenomena: training data memorization and various forms of forgetting. In memorization, models overfit specific training examples and become susceptible to privacy attacks. In forgetting, examples which appeared early in training are forgot…

Cited by 112SourcePDFScholar
2023

Why Is Public Pretraining Necessary for Private Model Training?

ICML 2023poster

In the privacy-utility tradeoff of a model trained on benchmark language and vision tasks, remarkable improvements have been widely reported when the model is pretrained on public data. Some gain is expected as these models inherit the benefits of transfer learning, which is the standard motivation…

Cited by 51SourcePDFScholar
2022

A Method to Reveal Speaker Identity in Distributed ASR Training, and How to Counter IT

ICASSP 2022accepted

End-to-end Automatic Speech Recognition (ASR) models are commonly trained over spoken utterances using optimization methods like Stochastic Gradient Descent (SGD). In distributed settings like Federated Learning, model training requires transmission of gradients over a network. In this work, we desi…

Cited by 0SourceScholar
2022

Public Data-Assisted Mirror Descent for Private Model Training

ICML 2022spotlight

In this paper, we revisit the problem of using in-distribution public data to improve the privacy/utility trade-offs for differentially private (DP) model training. (Here, public data refers to auxiliary data sets that have no privacy concerns.) We design a natural variant of DP mirror descent, wher…

Cited by 68SourcePDFScholar
2022

The Role of Adaptive Optimizers for Honest Private Hyperparameter Selection

AAAI 2022technical

Hyperparameter optimization is a ubiquitous challenge in machine learning, and the performance of a trained model depends crucially upon their effective selection. While a rich set of tools exist for this purpose, there are currently no practical hyperparameter selection methods under the constraint…

Cited by 43SourcePDFScholar
2021

Differentially Private Learning with Adaptive Clipping

NeurIPS 2021poster

Existing approaches for training neural networks with user-level differential privacy (e.g., DP Federated Averaging) in federated learning (FL) settings involve bounding the contribution of each user's model update by {\em clipping} it to some constant value. However there is no good {\em a priori}…

Cited by 431SourcePDFScholar
2021

Evading the Curse of Dimensionality in Unconstrained Private GLMs

AISTATS 2021poster

We revisit the well-studied problem of differentially private empirical risk minimization (ERM). We show that for unconstrained convex generalized linear models (GLMs), one can obtain an excess empirical risk of $\tilde O\left(\sqrt{\rank}/\epsilon n\right)$, where $\rank$ is the rank of the feature…

Cited by 92SourcePDFScholar
2021

Practical and Private (Deep) Learning Without Sampling or Shuffling

ICML 2021spotlight

We consider training models with differential privacy (DP) using mini-batch gradients. The existing state-of-the-art, Differentially Private Stochastic Gradient Descent (DP-SGD), requires \emph{privacy amplification by sampling or shuffling} to obtain the best privacy/accuracy/computation trade-offs…

Cited by 226SourcePDFScholar
2021

Revealing and Protecting Labels in Distributed Training

NeurIPS 2021poster

Distributed learning paradigms such as federated learning often involve transmission of model updates, or gradients, over a network, thereby avoiding transmission of private data. However, it is possible for sensitive information about the training data to be revealed from such gradients. Prior work…

2020

Guaranteed Validity for Empirical Approaches to Adaptive Data Analysis

AISTATS 2020poster

We design a general framework for answering adaptive statistical queries that focuses on providing explicit confidence intervals along with point estimates. Prior work in this area has either focused on providing tight confidence intervals for specific analyses, or providing general worst-case bound…

2020

Privacy Amplification via Random Check-Ins

NeurIPS 2020poster

Differentially Private Stochastic Gradient Descent (DP-SGD) forms a fundamental building block in many applications for learning over sensitive data. Two standard approaches, privacy amplification by subsampling, and privacy amplification by shuffling, permit adding lower noise in DP-SGD than via na…

Cited by 98SourcePDFScholar