arXiv Machine Learning

In-Context Bias Propagation in LLM-Based Tabular Data Generation

The paper investigates how biases present in in-context examples used by Large Language Models (LLMs) for synthetic tabular data generation can propagate to the generated data, causing global statistical distortions even when the biases are mild. It also explores an adversarial scenario where a malicious actor can inject bias through a subset of examples, thereby compromising the fairness of downstream classifiers for protected subgroups. The authors evaluate prompt-side mitigation strategies, such as preprocessing examples and instruction-based defenses, noting that while these can reduce disparity, LLMs remain highly sensitive to adversarial prompts, revealing a significant vulnerability in data generation pipelines for sensitive domains.

arXiv AI
Jun 26

Limited Reference, Reliable Generation: A Two-Component Framework for Tabular Data Generation in Low-Data Regimes

arXiv:2509. 09960v2 Announce Type: replace-cross Abstract: Synthetic tabular data generation is increasingly essential in machine learning, supporting downstream applications when real-world, high-quality tabular data is insufficient.

By Mingxuan Jiang, Keyang Chen, Yongxin Wang, Yongsheng Zhao, Ziyue Dai, Yicun Liu, Zeping Li, Qiuyang Zhang, Hongyi Nie, Hongbin Zhu, Sen Liu, Guangnan Ye, Hongfeng Chai
arXiv AI
Sep 1

Hidden Threat in Synthetic Data: Covert Targeted Bias Injection through Benign Text

The paper examines how synthetic data can be used to covertly inject targeted social biases into aligned large language models. By having a misaligned teacher model generate filtered synthetic datasets in domains like creative writing and code generation, the authors fine‑tune aligned student models and demonstrate that the benign‑looking data can transmit biases while preserving general task performance. The study highlights a security risk in synthetic data‑driven LLM training pipelines and proposes log‑linearity‑based scoring as a potential safeguard.

By Minkyung Cho, Jihyo Kim, SeungWoo Song, Junghun Yuk, Minjoon Kee, Hoyun Song, KyungTae Lim
arXiv AI
Sep 1

Watch your steps: Dormant Adversarial Behaviors that Activate upon LLM Finetuning

The paper introduces FAB, an attack that uses meta‑learning to embed dormant adversarial behaviors into large language models (LLMs). These behaviors remain inactive until the model is finetuned by downstream users, at which point the model can exhibit unwanted actions such as unsolicited advertising, jailbreakability, or over‑refusal. FAB is shown to be effective across multiple LLMs and resilient to various finetuning settings.

By Thibaud Gloaguen, Mark Vero, Robin Staab, Martin Vechev
arXiv Machine Learning
Jul 16

When T2I Synthetic Data Backfires: Amplified Privacy Risks in Real-Synthetic Mix Training

arXiv:2607. 13541v1 Announce Type: cross Abstract: To overcome data scarcity and privacy constraints in data collection, it has become standard practice across academia and industry to augment real training data with text-to-image (T2I)-generated synthetic data, a paradigm we term Real-Synthetic Mix-Training (RSMT).

By Na Li, Boyu Kuang, Hongsheng Hu, Liquan Chen, Hyoungshick Kim, Yansong Gao, Anmin Fu
arXiv Machine Learning
Oct 16

INCONVENIENT: A Benchmark to Assess LLM Generalization Capabilities from Convenience Samples

INCONVENIENT is a new benchmark that evaluates how machine‑learning models, especially large language models, generalize when trained on convenience samples that bias feature–target relationships. Unlike prior distribution‑shift tests that rely on natural domain splits, INCONVENIENT explicitly perturbs these relationships while keeping the deployment population unchanged, allowing controlled study of shift severity and direction. The benchmark covers 200 tabular classification and regression datasets and produces about 15,500 shifted training distributions, revealing significant performance degradation.

By Sara Rezaeimanesh, Chad Klochko, Kundan Thind, Mohammad Ghassemi
arXiv AI
3d ago

TextCloak: Safeguarding Data from Unauthorized LLM Fine-Tuning via RL-Driven Unlearnable Examples

TextCloak is a reinforcement‑learning driven framework that generates unlearnable examples (UEs) to protect textual data from unauthorized fine‑tuning of large language models (LLMs). It transforms clean text into perturbations that preserve meaning and naturalness while degrading the utility of models trained on them. Experiments on six datasets and nine LLMs show that TextCloak consistently impairs unauthorized fine‑tuning and remains robust across different architectures, training settings, and adaptive attacks.

By Chengshuai Zhao, Pingchuan Ma, Dawei Li, Bohan Jiang, Zhiyuan Yu, Zhen Tan, Huan Liu
arXiv AI
3d ago

LLMs Can Leak Training Data But Do They Want To? Evaluating Memorization Propensity in LLMs

The paper introduces PropMe, a framework that evaluates both the capability of large language models (LLMs) to reproduce training data via prefix attacks and their natural propensity to do so without adversarial prompting. Using SimpleTrace to compare every generation against the full indexed training corpus, the authors test models such as Comma, DFM Decoder, and OLMo3 32B across datasets like Common Pile, Dynaword, and Dolma3. Results show that natural sentence prompts produce less training text than prefix attacks, but unprompted or single-word prompts can reproduce as much or more, often involving duplicated licenses, code, and templates; continual pre‑training only modestly reduces verbatim reproduction.

By Gianluca Barmina, Peter Schneider-Kamp, Lukas Galke Poech