activity
20172025
most citedStochastic (Approximate) Proximal Point Methods: Convergence, Optimality, and Adaptivity

74 citations · 172 across the 28 of their papers we have counts for

collaborators

29 papers

cs.LG2025

Faster Rates for Private Adversarial Bandits

Hilal Asi, Vinod Raman, Kunal Talwar

We design new differentially private algorithms for the problems of adversarial bandits and bandits with expert advice. For adversarial bandits, we give a simple and efficient conv…

cs.CL2025

AdaBoN: Adaptive Best-of-N Alignment

Vinod Raman, Hilal Asi, Satyen Kale

Recent advances in test-time alignment methods, such as Best-of-N sampling, offer a simple and effective way to steer language models (LMs) toward preferred behaviors using reward…

cs.LG2025

On Privately Estimating a Single Parameter

Hilal Asi, John C. Duchi, Kunal Talwar

We investigate differentially private estimators for individual parameters within larger parametric models. While generic private estimators exist, the estimators we provide repose…

cs.LG2025

Tracking the Best Expert Privately

Aadirupa Saha, Vinod Raman, Hilal Asi

We design differentially private algorithms for the problem of prediction with expert advice under dynamic regret, also known as tracking the best expert. Our work addresses three…

cs.CR2025

PREAMBLE: Private and Efficient Aggregation via Block Sparse Vectors

Hilal Asi, Vitaly Feldman, Hannah Keller +2

We revisit the problem of secure aggregation of high-dimensional vectors in a two-server system such as Prio. These systems are typically used to aggregate vectors such as gradient…

cs.LG2024

Faster Algorithms for User-Level Private Stochastic Convex Optimization

Andrew Lowy, Daogao Liu, Hilal Asi

We study private stochastic convex optimization (SCO) under user-level differential privacy (DP) constraints. In this setting, there are users (e.g., cell phones), each possess…

cs.DS2024

Private Stochastic Convex Optimization with Heavy Tails: Near-Optimality from Simple Reductions

Hilal Asi, Daogao Liu, Kevin Tian

We study the problem of differentially private stochastic convex optimization (DP-SCO) with heavy-tailed gradients, where we assume a -moment bound on the Lipschitz…

cs.CR2024

Wally: Batched Private Nearest Neighbor Search at Scale

Hilal Asi, Fabian Boemer, Nicholas Genise +8

We present Wally, a batched private nearest-neighbor search protocol that uses differential privacy to break the linear computation barrier of fully-oblivious schemes. In Tiptoe, t…

cs.LG2024

Private Online Learning via Lazy Algorithms

Hilal Asi, Tomer Koren, Daogao Liu +1

We study the problem of private online learning, specifically, online prediction from experts (OPE) and online convex optimization (OCO). We propose a new transformation that trans…

cs.DS2024★ 1 cited

Private Vector Mean Estimation in the Shuffle Model: Optimal Rates Require Many Messages

Hilal Asi, Vitaly Feldman, Jelani Nelson +3

We study the problem of private vector mean estimation in the shuffle model of privacy where users each have a unit vector . We propose a new multi-mes…

cs.LG2024

DP-Dueling: Learning from Preference Feedback without Compromising User Privacy

Aadirupa Saha, Hilal Asi

We consider the well-studied dueling bandit problem, where a learner aims to identify near-optimal actions using pairwise comparisons, under the constraint of differential privacy.…

cs.LG2023

User-level Differentially Private Stochastic Convex Optimization: Efficient Algorithms with Optimal Rates

Hilal Asi, Daogao Liu

We study differentially private stochastic convex optimization (DP-SCO) under user-level privacy, where each user may hold multiple data items. Existing work for user-level DP-SCO…

cs.LG2023★ 1 cited

Fast Optimal Locally Private Mean Estimation via Random Projections

Hilal Asi, Vitaly Feldman, Jelani Nelson +2

We study the problem of locally private mean estimation of high-dimensional vectors in the Euclidean ball. Existing algorithms for this problem either incur sub-optimal error or ha…

cs.LG2023

Near-Optimal Algorithms for Private Online Optimization in the Realizable Regime

Hilal Asi, Vitaly Feldman, Tomer Koren +1

We consider online learning problems in the realizable setting, where there is a zero-loss solution, and propose new Differentially Private (DP) algorithms that obtain near-optimal…

cs.LG2023★ 5 cited

From Robustness to Privacy and Back

Hilal Asi, Jonathan Ullman, Lydia Zakynthinou

We study the relationship between two desiderata of algorithms in statistical inference and machine learning: differential privacy and robustness to adversarial data corruptions. T…

cs.LG2022★ 1 cited

Private optimization in the interpolation regime: faster rates and hardness results

Hilal Asi, Karan Chadha, Gary Cheng +1

In non-private stochastic convex optimization, stochastic gradient methods converge much faster on interpolation problems -- problems where there exists a solution that simultaneou…

cs.LG2022

Private Online Prediction from Experts: Separations and Faster Rates

Hilal Asi, Vitaly Feldman, Tomer Koren +1

Online prediction from experts is a fundamental problem in machine learning and several works have studied this problem under privacy constraints. We propose and analyze new algori…

math.ST2022

How many labelers do you have? A closer look at gold-standard labels

Chen Cheng, Hilal Asi, John Duchi

The construction of most supervised learning datasets revolves around collecting multiple labels for each instance, then aggregating the labels to form a type of "true" label. We q…

cs.LG2022★ 4 cited

Optimal Algorithms for Mean Estimation under Local Differential Privacy

Hilal Asi, Vitaly Feldman, Kunal Talwar

We study the problem of mean estimation of -bounded vectors under the constraint of local differential privacy. While the literature has a variety of algorithms that achiev…

cs.LG2021★ 2 cited

Adapting to Function Difficulty and Growth Conditions in Private Optimization

Hilal Asi, Daniel Levy, John Duchi

We develop algorithms for private stochastic convex optimization that adapt to the hardness of the specific function we wish to optimize. While previous work provide worst-case bou…

cs.LG2021★ 12 cited

Private Adaptive Gradient Methods for Convex Optimization

Hilal Asi, John Duchi, Alireza Fallah +2

We study adaptive methods for differentially private convex optimization, proposing and analyzing differentially private variants of a Stochastic Gradient Descent (SGD) algorithm w…

math.OC2021

Stochastic Bias-Reduced Gradient Methods

Hilal Asi, Yair Carmon, Arun Jambulapati +2

We develop a new primitive for stochastic optimization: a low-bias, low-cost estimator of the minimizer of any Lipschitz strongly-convex function. In particular, we use a…

cs.LG2021★ 5 cited

Private Stochastic Convex Optimization: Optimal Rates in Geometry

Hilal Asi, Vitaly Feldman, Tomer Koren +1

Stochastic convex optimization over an -bounded domain is ubiquitous in machine learning applications such as LASSO but remains poorly understood when learning with differe…

cs.CR2020★ 4 cited

Near Instance-Optimality in Differential Privacy

Hilal Asi, John C. Duchi

We develop two notions of instance optimality in differential privacy, inspired by classical statistical theory: one by defining a local minimax risk and the other by considering u…