Detecting Training Data of Large Language Models via Expectation Maximization
On the map: LLM safety and security → Membership inference attacks
Abstract (arXiv)
Membership inference attacks (MIAs) aim to determine whether a specific example was used to train a given language model. While prior work has explored prompt-based attacks such as ReCALL, these methods rely heavily on the assumption that using known non-members as prompts reliably suppresses the model's responses to non-member queries. We propose EM-MIA, a new membership inference approach that iteratively refines prefix effectiveness and membership scores using an expectation-maximization strategy without requiring labeled non-member examples. To support controlled evaluation, we introduce OLMoMIA, a benchmark that enables analysis of MIA robustness under systematically varied distributional overlap and difficulty. Experiments on WikiMIA and OLMoMIA show that EM-MIA outperforms existing baselines, particularly in settings with clear distributional separability. We highlight scenarios where EM-MIA succeeds in practical settings with partial distributional overlap, while failure cases expose fundamental limitations of current MIA methods under near-identical conditions. We release our code and evaluation pipeline to encourage reproducible and robust MIA research.
Key facts. Cited by 13 papers in the map (data through 7 Oct 2026). Placed in Membership inference attacks, one of 12 directions in LLM safety and security. Builds on 59 of its 77 references that are in the map. First posted on arXiv 10 Oct 2024.
Builds on
59 of 77 references.
Closest ancestors · 15
Same direction, newest first
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- 2024ReCaLL: Membership Inference via Relative Conditional Log-Likelihoods23 Jun
- 2024Semantic Membership Inference Attack against Large Language Models14 Jun
- 2024LLM Dataset Inference: Did you train on my dataset?10 Jun
- 2024Sampling-based Pseudo-Likelihood for Membership Inference Attacks17 Apr
- 2024Do Membership Inference Attacks Work on Large Language Models?12 Feb
- 2023Did the Neurons Read your Book? Document-level Membership Inference for Large Language Models23 Oct
- 2023Membership Inference Attacks against Language Models via Neighbourhood Comparison29 May
- 2022Quantifying Privacy Risks of Masked Language Models Using Membership Inference Attacks8 Mar
- 2021Membership Inference Attacks From First Principles7 Dec
3 more
Other references · 44
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- 2020The Pile: An 800GB Dataset of Diverse Text for Language Modelingcited by 2,346
- 2016Membership Inference Attacks against Machine Learning Modelscited by 2,221
- 2020Extracting Training Data from Large Language Modelscited by 2,144
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- 2024DE-COP: Detecting Copyrighted Content in Language Models Training Datacited by 72
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Citing papers per year: 2024: 1; 2025: 7; 2026: 5.
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- 2025ReLearn: Unlearning via Learning for Large Language Modelscited by 20
- 2024LUMIA: Linear probing for Unimodal and MultiModal Membership Inference Attacks leveraging internal LLM statescited by 8
- 2025Beyond Data Privacy: New Privacy Risks for Large Language Modelscited by 6
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- 2026Pretraining Data Exposure in Large Language Models: A Survey of Membership Inference, Data Contamination, and Security Implications21 May 2026
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- 2026Toward Reliable, Safe, and Secure LLMs for Scientific Applications18 Mar 2026
- 2025In-Context Probing for Membership Inference in Fine-Tuned Language Models18 Dec 2025
- 2025Black Box Absorption: LLMs Undermining Innovative Ideas23 Oct 2025
- 2025GPT and Prejudice: A Sparse Approach to Understanding Learned Representations in Large Language Models24 Sep 2025
- 2025Beyond Data Privacy: New Privacy Risks for Large Language Models16 Sep 2025
- 2025Efficient Knowledge Graph Unlearning with Zeroth-order Information19 Aug 2025
- 2025A Systematic Analysis of Base Model Choice for Reward Modeling16 May 2025
- 2025ReLearn: Unlearning via Learning for Large Language Models16 Feb 2025
- 2025ReLearn: Unlearning via Learning for Large Language Modelscited by 20
- 2024LUMIA: Linear probing for Unimodal and MultiModal Membership Inference Attacks leveraging internal LLM statescited by 8
- 2025In-Context Probing for Membership Inference in Fine-Tuned Language Modelscited by 3
- 2025Efficient Knowledge Graph Unlearning with Zeroth-order Informationcited by 2
- 2026CheckMIABench: Firm Foundations For Membership Inference Attacks on Language Modelscited by 2
- 2026Pretraining Data Exposure in Large Language Models: A Survey of Membership Inference, Data Contamination, and Security Implicationscited by 1
- 2026LLM Unlearning for Cyber Defense: A Survey on Methods, Challenges, and Emerging Threatscited by 0
- 2026LLM Unlearning for Cyber Defense: A Survey on Methods, Challenges, and Emerging Threats23 Jun 2026
- 2026CheckMIABench: Firm Foundations For Membership Inference Attacks on Language Models16 Jun 2026
- 2026Pretraining Data Exposure in Large Language Models: A Survey of Membership Inference, Data Contamination, and Security Implications21 May 2026
- 2025In-Context Probing for Membership Inference in Fine-Tuned Language Models18 Dec 2025
- 2025Efficient Knowledge Graph Unlearning with Zeroth-order Information19 Aug 2025
- 2025ReLearn: Unlearning via Learning for Large Language Models16 Feb 2025
- 2024LUMIA: Linear probing for Unimodal and MultiModal Membership Inference Attacks leveraging internal LLM states29 Nov 2024
- 2025Beyond Data Privacy: New Privacy Risks for Large Language Modelscited by 6
- 2025Black Box Absorption: LLMs Undermining Innovative Ideascited by 1
- 2025GPT and Prejudice: A Sparse Approach to Understanding Learned Representations in Large Language Modelscited by 0
- 2026Detecting Data Contamination in Large Language Modelscited by 0
- 2026Detecting Data Contamination in Large Language Models21 Apr 2026
- 2025Black Box Absorption: LLMs Undermining Innovative Ideas23 Oct 2025
- 2025GPT and Prejudice: A Sparse Approach to Understanding Learned Representations in Large Language Models24 Sep 2025
- 2025Beyond Data Privacy: New Privacy Risks for Large Language Models16 Sep 2025