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Enayat Ullah

12 accepted papers

2026

Efficient DP-SGD for LLMs with Randomized Clipping

ICML 2026poster

Large language models (LLMs) are trained on vast datasets that may contain sensitive information. Differential privacy (DP), the de facto standard for formal privacy guarantees, provides a principled framework for training LLMs with provable privacy protection. However, state-of-the-art DP training …

Cited by 0SourceScholar
2024

Adversarially Robust Multi-task Representation Learning

NeurIPS 2024poster

We study adversarially robust transfer learning, wherein, given labeled data on multiple (source) tasks, the goal is to train a model with small robust error on a previously unseen (target) task. In particular, we consider a multi-task representation learning (MTRL) setting, i.e., we assume that the…

Cited by 1SourcePDFScholar
2024

Public-data Assisted Private Stochastic Optimization: Power and Limitations

NeurIPS 2024poster

We study the limits and capability of public-data assisted differentially private (PA-DP) algorithms. Specifically, we focus on the problem of stochastic convex optimization (SCO) with either labeled or unlabeled public data. For complete/labeled public data, we show that any $(\epsilon,\delta)$-PA…

Cited by 3SourcePDFScholar
2023

Faster Rates of Convergence to Stationary Points in Differentially Private Optimization

ICML 2023poster

We study the problem of approximating stationary points of Lipschitz and smooth functions under $(\varepsilon,\delta)$-differential privacy (DP) in both the finite-sum and stochastic settings. A point $\widehat{w}$ is called an $\alpha$-stationary point of a function $F:\mathbb{R}^d\rightarrow\mathb…

Cited by 34SourcePDFScholar
2023

Optimistic Rates for Multi-Task Representation Learning

NeurIPS 2023poster

We study the problem of transfer learning via Multi-Task Representation Learning (MTRL), wherein multiple source tasks are used to learn a good common representation, and a predictor is trained on top of it for the target task. Under standard regularity assumptions on the loss function and task dive…

Cited by 13SourcePDFScholar
2023

Private Federated Learning with Autotuned Compression

ICML 2023poster

We propose new techniques for reducing communication in private federated learning without the need for setting or tuning compression rates. Our on-the-fly methods automatically adjust the compression rate based on the error induced during training, while maintaining provable privacy guarantees thro…

2022

Differentially Private Generalized Linear Models Revisited

NeurIPS 2022accept

We study the problem of $(\epsilon,\delta)$-differentially private learning of linear predictors with convex losses. We provide results for two subclasses of loss functions. The first case is when the loss is smooth and non-negative but not necessarily Lipschitz (such as the squared loss). For this…

Cited by 25SourcePDFScholar
2020

FetchSGD: Communication-Efficient Federated Learning with Sketching

ICML 2020poster

Existing approaches to federated learning suffer from a communication bottleneck as well as convergence issues due to sparse client participation. In this paper we introduce a novel algorithm,called FetchSGD, to overcome these challenges. FetchSGD compresses model updates using a Count Sketch, and t…

Cited by 464SourcePDFScholar
2019

Communication-efficient Distributed SGD with Sketching

NeurIPS 2019poster

Large-scale distributed training of neural networks is often limited by network bandwidth, wherein the communication time overwhelms the local computation time. Motivated by the success of sketching methods in sub-linear/streaming algorithms, we introduce Sketched-SGD, an algorithm for carrying out…

2018

Streaming Kernel PCA with $\tilde{O}(\sqrt{n})$ Random Features

NeurIPS 2018poster

We study the statistical and computational aspects of kernel principal component analysis using random Fourier features and show that under mild assumptions, $O(\sqrt{n} \log n)$ features suffices to achieve $O(1/\epsilon^2)$ sample complexity. Furthermore, we give a memory efficient streaming algor…