# Overlearning Reveals Sensitive Attributes

arXiv: https://arxiv.org/abs/1905.11742 · HTML: https://mlsanity.com/paper/1905.11742/

## Key facts

- Cited by 76 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 28 May 2019.

## Built on by (most cited first, 30 of 76)

- [Graph Unlearning](https://mlsanity.com/paper/2103.14991/) (2021)
- [The Distributed Discrete Gaussian Mechanism for Federated Learning with Secure Aggregation](https://mlsanity.com/paper/2102.06387/) (2021)
- [Dataset Inference: Ownership Resolution in Machine Learning](https://mlsanity.com/paper/2104.10706/) (2021)
- [Vertical Federated Learning: Concepts, Advances and Challenges](https://mlsanity.com/paper/2211.12814/) (2022)
- [ML-Doctor: Holistic Risk Assessment of Inference Attacks Against Machine Learning Models](https://mlsanity.com/paper/2102.02551/) (2021)
- [Node-Level Membership Inference Attacks Against Graph Neural Networks](https://mlsanity.com/paper/2102.05429/) (2021)
- [Privacy in Large Language Models: Attacks, Defenses and Future Directions](https://mlsanity.com/paper/2310.10383/) (2023)
- [Bounding Training Data Reconstruction in DP-SGD](https://mlsanity.com/paper/2302.07225/) (2023)
- [Survey: Leakage and Privacy at Inference Time](https://mlsanity.com/paper/2107.01614/) (2021)
- [Prompt Stealing Attacks Against Large Language Models](https://mlsanity.com/paper/2402.12959/) (2024)
- [Fair Normalizing Flows](https://mlsanity.com/paper/2106.05937/) (2021)
- [Quantifying and Mitigating Privacy Risks of Contrastive Learning](https://mlsanity.com/paper/2102.04140/) (2021)
- [Integration of Large Language Models and Federated Learning](https://mlsanity.com/paper/2307.08925/) (2023)
- [Honest-but-Curious Nets: Sensitive Attributes of Private Inputs Can Be Secretly Coded into the Classifiers' Outputs](https://mlsanity.com/paper/2105.12049/) (2021)
- [Membership-Doctor: Comprehensive Assessment of Membership Inference Against Machine Learning Models](https://mlsanity.com/paper/2208.10445/) (2022)
- [Inferring Sensitive Attributes from Model Explanations](https://mlsanity.com/paper/2208.09967/) (2022)
- [Purifier: Defending Data Inference Attacks via Transforming Confidence Scores](https://mlsanity.com/paper/2212.00612/) (2022)
- [No Free Lunch Theorem for Privacy-Preserving LLM Inference](https://mlsanity.com/paper/2405.20681/) (2024)
- [You Don't Know My Favorite Color: Preventing Dialogue Representations from Revealing Speakers' Private Personas](https://mlsanity.com/paper/2205.10228/) (2022)
- [Marich: A Query-efficient Distributionally Equivalent Model Extraction Attack using Public Data](https://mlsanity.com/paper/2302.08466/) (2023)
- [Are Two Heads the Same as One? Identifying Disparate Treatment in Fair Neural Networks](https://mlsanity.com/paper/2204.04440/) (2022)
- [Semi-Leak: Membership Inference Attacks Against Semi-supervised Learning](https://mlsanity.com/paper/2207.12535/) (2022)
- [Fairness Properties of Face Recognition and Obfuscation Systems](https://mlsanity.com/paper/2108.02707/) (2021)
- [On the Alignment of Group Fairness with Attribute Privacy](https://mlsanity.com/paper/2211.10209/) (2022)
- [AUTOLYCUS: Exploiting Explainable AI (XAI) for Model Extraction Attacks against Interpretable Models](https://mlsanity.com/paper/2302.02162/) (2023)
- [How Does a Deep Learning Model Architecture Impact Its Privacy? A Comprehensive Study of Privacy Attacks on CNNs and Transformers](https://mlsanity.com/paper/2210.11049/) (2022)
- [Scalable Infomin Learning](https://mlsanity.com/paper/2302.10701/) (2023)
- [VFLAIR: A Research Library and Benchmark for Vertical Federated Learning](https://mlsanity.com/paper/2310.09827/) (2023)
- [Skellam Mixture Mechanism: a Novel Approach to Federated Learning with Differential Privacy](https://mlsanity.com/paper/2212.04371/) (2022)
- [A Method to Facilitate Membership Inference Attacks in Deep Learning Models](https://mlsanity.com/paper/2407.01919/) (2024)

## Abstract (arXiv)

"Overlearning" means that a model trained for a seemingly simple objective implicitly learns to recognize attributes and concepts that are (1) not part of the learning objective, and (2) sensitive from a privacy or bias perspective. For example, a binary gender classifier of facial images also learns to recognize racestextemdash even races that are not represented in the training datatextemdash and identities. We demonstrate overlearning in several vision and NLP models and analyze its harmful consequences. First, inference-time representations of an overlearned model reveal sensitive attributes of the input, breaking privacy protections such as model partitioning. Second, an overlearned model can be "re-purposed" for a different, privacy-violating task even in the absence of the original training data. We show that overlearning is intrinsic for some tasks and cannot be prevented by censoring unwanted attributes. Finally, we investigate where, when, and why overlearning happens during model training.
