Retracing the Past: LLMs Emit Training Data When They Get Lost

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Ko, Myeongseob, Billa, Nikhil Reddy, Nguyen, Adam, Fleming, Charles, Jin, Ming, Jia, Ruoxi
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866917069047463936
author Ko, Myeongseob
Billa, Nikhil Reddy
Nguyen, Adam
Fleming, Charles
Jin, Ming
Jia, Ruoxi
author_facet Ko, Myeongseob
Billa, Nikhil Reddy
Nguyen, Adam
Fleming, Charles
Jin, Ming
Jia, Ruoxi
contents The memorization of training data in large language models (LLMs) poses significant privacy and copyright concerns. Existing data extraction methods, particularly heuristic-based divergence attacks, often exhibit limited success and offer limited insight into the fundamental drivers of memorization leakage. This paper introduces Confusion-Inducing Attacks (CIA), a principled framework for extracting memorized data by systematically maximizing model uncertainty. We empirically demonstrate that the emission of memorized text during divergence is preceded by a sustained spike in token-level prediction entropy. CIA leverages this insight by optimizing input snippets to deliberately induce this consecutive high-entropy state. For aligned LLMs, we further propose Mismatched Supervised Fine-tuning (SFT) to simultaneously weaken their alignment and induce targeted confusion, thereby increasing susceptibility to our attacks. Experiments on various unaligned and aligned LLMs demonstrate that our proposed attacks outperform existing baselines in extracting verbatim and near-verbatim training data without requiring prior knowledge of the training data. Our findings highlight persistent memorization risks across various LLMs and offer a more systematic method for assessing these vulnerabilities.
format Preprint
id arxiv_https___arxiv_org_abs_2511_05518
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Retracing the Past: LLMs Emit Training Data When They Get Lost
Ko, Myeongseob
Billa, Nikhil Reddy
Nguyen, Adam
Fleming, Charles
Jin, Ming
Jia, Ruoxi
Computation and Language
Artificial Intelligence
The memorization of training data in large language models (LLMs) poses significant privacy and copyright concerns. Existing data extraction methods, particularly heuristic-based divergence attacks, often exhibit limited success and offer limited insight into the fundamental drivers of memorization leakage. This paper introduces Confusion-Inducing Attacks (CIA), a principled framework for extracting memorized data by systematically maximizing model uncertainty. We empirically demonstrate that the emission of memorized text during divergence is preceded by a sustained spike in token-level prediction entropy. CIA leverages this insight by optimizing input snippets to deliberately induce this consecutive high-entropy state. For aligned LLMs, we further propose Mismatched Supervised Fine-tuning (SFT) to simultaneously weaken their alignment and induce targeted confusion, thereby increasing susceptibility to our attacks. Experiments on various unaligned and aligned LLMs demonstrate that our proposed attacks outperform existing baselines in extracting verbatim and near-verbatim training data without requiring prior knowledge of the training data. Our findings highlight persistent memorization risks across various LLMs and offer a more systematic method for assessing these vulnerabilities.
title Retracing the Past: LLMs Emit Training Data When They Get Lost
topic Computation and Language
Artificial Intelligence
url https://arxiv.org/abs/2511.05518