Personalized Privacy Control in LLMs via Attention Head Intervention

Junseok Kim, Nakyeong Yang, Kyomin Jung


Abstract
The rise of agentic AI enables LLMs to access diverse user data, raising critical privacy concerns. Prior work on contextual privacy studies whether LLMs regulate information disclosure according to context-dependent norms. However, acceptable disclosure boundaries may vary across users even within the same context. To address this limitation, we introduce personalized privacy, which incorporates user-specific disclosure preferences into privacy control. We further present P3Bench (Personalized Privacy Preservation Benchmark), a novel benchmark extending contextual privacy policies with personalized disclosure policies. Experiments show that prompt-based policies fail to reliably enforce personalized privacy policies, with Qwen2.5-7B and Gemma3-4B showing average policy ignorance ratios of 51.25% and 74.28%, respectively. Finally, to address this problem, we propose Repair, a robust inference-time attention head intervention method that adjusts disclosure behavior toward policy-consistent responses. Our method significantly improves adherence to user-specific privacy preferences by reducing cases where the model fails to follow the given policy.
Anthology ID:
2026.findings-emnlp.1540
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
32758–32779
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1540/
DOI:
Bibkey:
Cite (ACL):
Junseok Kim, Nakyeong Yang, and Kyomin Jung. 2026. Personalized Privacy Control in LLMs via Attention Head Intervention. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 32758–32779, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Personalized Privacy Control in LLMs via Attention Head Intervention (Kim et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1540.pdf