The Last Iterate Advantage: Empirical Auditing and Principled Heuristic Analysis of Differentially Private SGD

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Steinke, Thomas, Nasr, Milad, Ganesh, Arun, Balle, Borja, Choquette-Choo, Christopher A., Jagielski, Matthew, Hayes, Jamie, Thakurta, Abhradeep Guha, Smith, Adam, Terzis, Andreas
Natura: Preprint
Pubblicazione: 2024
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866929743742369792
author Steinke, Thomas
Nasr, Milad
Ganesh, Arun
Balle, Borja
Choquette-Choo, Christopher A.
Jagielski, Matthew
Hayes, Jamie
Thakurta, Abhradeep Guha
Smith, Adam
Terzis, Andreas
author_facet Steinke, Thomas
Nasr, Milad
Ganesh, Arun
Balle, Borja
Choquette-Choo, Christopher A.
Jagielski, Matthew
Hayes, Jamie
Thakurta, Abhradeep Guha
Smith, Adam
Terzis, Andreas
contents We propose a simple heuristic privacy analysis of noisy clipped stochastic gradient descent (DP-SGD) in the setting where only the last iterate is released and the intermediate iterates remain hidden. Namely, our heuristic assumes a linear structure for the model. We show experimentally that our heuristic is predictive of the outcome of privacy auditing applied to various training procedures. Thus it can be used prior to training as a rough estimate of the final privacy leakage. We also probe the limitations of our heuristic by providing some artificial counterexamples where it underestimates the privacy leakage. The standard composition-based privacy analysis of DP-SGD effectively assumes that the adversary has access to all intermediate iterates, which is often unrealistic. However, this analysis remains the state of the art in practice. While our heuristic does not replace a rigorous privacy analysis, it illustrates the large gap between the best theoretical upper bounds and the privacy auditing lower bounds and sets a target for further work to improve the theoretical privacy analyses. We also empirically support our heuristic and show existing privacy auditing attacks are bounded by our heuristic analysis in both vision and language tasks.
format Preprint
id arxiv_https___arxiv_org_abs_2410_06186
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle The Last Iterate Advantage: Empirical Auditing and Principled Heuristic Analysis of Differentially Private SGD
Steinke, Thomas
Nasr, Milad
Ganesh, Arun
Balle, Borja
Choquette-Choo, Christopher A.
Jagielski, Matthew
Hayes, Jamie
Thakurta, Abhradeep Guha
Smith, Adam
Terzis, Andreas
Cryptography and Security
Machine Learning
We propose a simple heuristic privacy analysis of noisy clipped stochastic gradient descent (DP-SGD) in the setting where only the last iterate is released and the intermediate iterates remain hidden. Namely, our heuristic assumes a linear structure for the model. We show experimentally that our heuristic is predictive of the outcome of privacy auditing applied to various training procedures. Thus it can be used prior to training as a rough estimate of the final privacy leakage. We also probe the limitations of our heuristic by providing some artificial counterexamples where it underestimates the privacy leakage. The standard composition-based privacy analysis of DP-SGD effectively assumes that the adversary has access to all intermediate iterates, which is often unrealistic. However, this analysis remains the state of the art in practice. While our heuristic does not replace a rigorous privacy analysis, it illustrates the large gap between the best theoretical upper bounds and the privacy auditing lower bounds and sets a target for further work to improve the theoretical privacy analyses. We also empirically support our heuristic and show existing privacy auditing attacks are bounded by our heuristic analysis in both vision and language tasks.
title The Last Iterate Advantage: Empirical Auditing and Principled Heuristic Analysis of Differentially Private SGD
topic Cryptography and Security
Machine Learning
url https://arxiv.org/abs/2410.06186