No Prior, No Leakage: Revisiting Reconstruction Attacks in Trained Neural Networks

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Refael, Yehonatan, Smorodinsky, Guy, Lindenbaum, Ofir, Safran, Itay
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911176234893312
author Refael, Yehonatan
Smorodinsky, Guy
Lindenbaum, Ofir
Safran, Itay
author_facet Refael, Yehonatan
Smorodinsky, Guy
Lindenbaum, Ofir
Safran, Itay
contents The memorization of training data by neural networks raises pressing concerns for privacy and security. Recent work has shown that, under certain conditions, portions of the training set can be reconstructed directly from model parameters. Some of these methods exploit implicit bias toward margin maximization, suggesting that properties often regarded as beneficial for generalization may actually compromise privacy. Yet despite striking empirical demonstrations, the reliability of these attacks remains poorly understood and lacks a solid theoretical foundation. In this work, we take a complementary perspective: rather than designing stronger attacks, we analyze the inherent weaknesses and limitations of existing reconstruction methods and identify conditions under which they fail. We rigorously prove that, without incorporating prior knowledge about the data, there exist infinitely many alternative solutions that may lie arbitrarily far from the true training set, rendering reconstruction fundamentally unreliable. Empirically, we further demonstrate that exact duplication of training examples occurs only by chance. Our results refine the theoretical understanding of when training set leakage is possible and offer new insights into mitigating reconstruction attacks. Remarkably, we demonstrate that networks trained more extensively, and therefore satisfying implicit bias conditions more strongly -- are, in fact, less susceptible to reconstruction attacks, reconciling privacy with the need for strong generalization in this setting.
format Preprint
id arxiv_https___arxiv_org_abs_2509_21296
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle No Prior, No Leakage: Revisiting Reconstruction Attacks in Trained Neural Networks
Refael, Yehonatan
Smorodinsky, Guy
Lindenbaum, Ofir
Safran, Itay
Machine Learning
Artificial Intelligence
The memorization of training data by neural networks raises pressing concerns for privacy and security. Recent work has shown that, under certain conditions, portions of the training set can be reconstructed directly from model parameters. Some of these methods exploit implicit bias toward margin maximization, suggesting that properties often regarded as beneficial for generalization may actually compromise privacy. Yet despite striking empirical demonstrations, the reliability of these attacks remains poorly understood and lacks a solid theoretical foundation. In this work, we take a complementary perspective: rather than designing stronger attacks, we analyze the inherent weaknesses and limitations of existing reconstruction methods and identify conditions under which they fail. We rigorously prove that, without incorporating prior knowledge about the data, there exist infinitely many alternative solutions that may lie arbitrarily far from the true training set, rendering reconstruction fundamentally unreliable. Empirically, we further demonstrate that exact duplication of training examples occurs only by chance. Our results refine the theoretical understanding of when training set leakage is possible and offer new insights into mitigating reconstruction attacks. Remarkably, we demonstrate that networks trained more extensively, and therefore satisfying implicit bias conditions more strongly -- are, in fact, less susceptible to reconstruction attacks, reconciling privacy with the need for strong generalization in this setting.
title No Prior, No Leakage: Revisiting Reconstruction Attacks in Trained Neural Networks
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2509.21296