Differentially Private Spectral Graph Clustering: Balancing Privacy, Accuracy, and Efficiency

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Koskela, Antti, Seif, Mohamed, Poor, H. Vincent, Goldsmith, Andrea J.
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913108812890112
author Koskela, Antti
Seif, Mohamed
Poor, H. Vincent
Goldsmith, Andrea J.
author_facet Koskela, Antti
Seif, Mohamed
Poor, H. Vincent
Goldsmith, Andrea J.
contents We study spectral graph clustering under edge differential privacy. We propose a matrix shuffling mechanism that combines randomized edge flipping with a random permutation of the adjacency matrix. While edge flipping alone provides only a constant $\varepsilon$ guarantee as the graph grows, shuffling amplifies privacy so that the effective $\varepsilon$ tends to zero with the number of nodes. We develop a unified error analysis framework -- based on Davis--Kahan perturbation theory and a classification-margin bound -- that gives explicit misclassification rates for all the mechanisms considered as a function of the privacy budget, eigengap, and number of communities. Applying this framework, we show that the matrix shuffling mechanism achieves an error rate scaling of $\tilde{O}(1/n)$, a clear improvement over two canonical DP baselines from the private PCA literature: the Gaussian mechanism applied directly to the adjacency matrix (Analyze Gauss) and the noisy power method, both of which scale as $\tilde{O}(1)$ in $n$. We further propose a private spectral gap detection algorithm for estimating the number of communities. Experiments on synthetic and real-world networks validate our theoretical findings.
format Preprint
id arxiv_https___arxiv_org_abs_2510_07136
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Differentially Private Spectral Graph Clustering: Balancing Privacy, Accuracy, and Efficiency
Koskela, Antti
Seif, Mohamed
Poor, H. Vincent
Goldsmith, Andrea J.
Information Theory
Cryptography and Security
Machine Learning
Social and Information Networks
We study spectral graph clustering under edge differential privacy. We propose a matrix shuffling mechanism that combines randomized edge flipping with a random permutation of the adjacency matrix. While edge flipping alone provides only a constant $\varepsilon$ guarantee as the graph grows, shuffling amplifies privacy so that the effective $\varepsilon$ tends to zero with the number of nodes. We develop a unified error analysis framework -- based on Davis--Kahan perturbation theory and a classification-margin bound -- that gives explicit misclassification rates for all the mechanisms considered as a function of the privacy budget, eigengap, and number of communities. Applying this framework, we show that the matrix shuffling mechanism achieves an error rate scaling of $\tilde{O}(1/n)$, a clear improvement over two canonical DP baselines from the private PCA literature: the Gaussian mechanism applied directly to the adjacency matrix (Analyze Gauss) and the noisy power method, both of which scale as $\tilde{O}(1)$ in $n$. We further propose a private spectral gap detection algorithm for estimating the number of communities. Experiments on synthetic and real-world networks validate our theoretical findings.
title Differentially Private Spectral Graph Clustering: Balancing Privacy, Accuracy, and Efficiency
topic Information Theory
Cryptography and Security
Machine Learning
Social and Information Networks
url https://arxiv.org/abs/2510.07136