activity
20212026
most citedBetter Differentially Private Approximate Histograms and Heavy Hitters using the Misra-Gries Sketch

1 citations · 1 across the 7 of their papers we have counts for

collaborators

9 papers

cs.LG2026

Lumberjack: Better Differentially Private Random Forests through Heavy Hitter Detection in Trees

Christian Janos Lebeda, David Erb, Tudor Cebere +1

Random forests are widely used in fields involving sensitive tabular data, but existing approaches to enforcing differential privacy (DP) typically degrade performance to the point…

cs.DS2025

Weighted Fourier Factorizations: Optimal Gaussian Noise for Differentially Private Marginal and Product Queries

Christian Janos Lebeda, Aleksandar Nikolov, Haohua Tang

We revisit the task of releasing marginal queries under differential privacy with additive (correlated) Gaussian noise. We first give a construction for answering arbitrary workloa…

cs.DS2024

The Correlated Gaussian Sparse Histogram Mechanism

Christian Janos Lebeda, Lukas Retschmeier

We consider the problem of releasing a sparse histogram under -differential privacy. The stability histogram independently adds noise from a Laplace or Gaussian d…

cs.DS2024

Testing Identity of Distributions under Kolmogorov Distance in Polylogarithmic Space

Christian Janos Lebeda, Jakub Tětek

Suppose we have a sample from a distribution and we want to test whether for a fixed distribution . Specifically, we want to reject with constant probability, if…

cs.CR2024

Better Gaussian Mechanism using Correlated Noise

Christian Janos Lebeda

We present a simple variant of the Gaussian mechanism for answering differentially private queries when the sensitivity space has a certain common structure. Our motivating problem…

cs.CR2024

Avoiding Pitfalls for Privacy Accounting of Subsampled Mechanisms under Composition

Christian Janos Lebeda, Matthew Regehr, Gautam Kamath +1

We consider the problem of computing tight privacy guarantees for the composition of subsampled differentially private mechanisms. Recent algorithms can numerically compute the pri…

cs.CR2023

PLAN: Variance-Aware Private Mean Estimation

Martin Aumüller, Christian Janos Lebeda, Boel Nelson +1

Differentially private mean estimation is an important building block in privacy-preserving algorithms for data analysis and machine learning. Though the trade-off between privacy…

cs.DS2023★ 1 cited

Better Differentially Private Approximate Histograms and Heavy Hitters using the Misra-Gries Sketch

Christian Janos Lebeda, Jakub Tětek

We consider the problem of computing differentially private approximate histograms and heavy hitters in a stream of elements. In the non-private setting, this is often done using t…

cs.CR2021

Differentially Private Sparse Vectors with Low Error, Optimal Space, and Fast Access

Martin Aumüller, Christian Janos Lebeda, Rasmus Pagh

Representing a sparse histogram, or more generally a sparse vector, is a fundamental task in differential privacy. An ideal solution would use space close to information-theoretica…