vix.ing · top · new · best · stats · spec

Optimal Pure Differentially Private Sparse Histograms in Deterministic Linear Time

2025/07/22 by Kerschbaum, Florian, Lee, Steven, Wu, Hao
#Cryptography and Security (cs.CR) #Data Structures and Algorithms (cs.DS) #FOS: Computer and information sciences

paper · doi:10.48550/arxiv.2507.17017

Abstract

We present an algorithm that releases a pure differentially private (under the replacement neighboring relation) sparse histogram for n participants over a domain of size d ≫ n. Our method achieves the optimal ℓ_∞-estimation error and runs in strictly O(n) time in the Word-RAM model, improving upon the previous best deterministic-time bound of O(n2) and resolving the open problem of breaking this quadratic barrier (Balcer and Vadhan, 2019). Moreover, the algorithm admits an efficient circuit implementation, enabling the first near-linear communication and computation cost pure DP histogram MPC protocol with optimal ℓ_∞-estimation error. Central to our algorithm is a novel **private item blanket** technique with target-length padding, which hides differences in the supports of neighboring histograms while remaining efficiently implementable.

Citations

Related