Privacy protection via large language model unlearning: methods, evaluation, and challenges

Zhang Lei1,2,3
Zhang Qiang1,2,3
Qiao Junzhao1,2,3
Wu Mingxi1,2,3
Zhang Ning1,2,3
1. School of Information &Electronic Technology, Jiamusi University, Jiamusi Heilongjiang 154000, China
2. Heilongjiang Province Key Laboratory of Autonomous Intelligence & Information Processing, School of Information & Electronic Technology, Jiamusi University, Jiamusi Heilongjiang 154007, China
3. Jiamusi Key Laboratory of Satellite Navigation Technology & Equipment Engineering Technology, Jiamusi Heilongjiang 154007, China

Abstract

The extensive deployment of large language models (LLMs) has heightened privacy risks such as membership inference and model inversion, making compliance with regulations including the right to be forgotten a key bottleneck in practice. Machine unlearning (MU) , which removes the influence of specific data after training, addresses this need for dynamic data deletion. This paper systematically surveyed MU methods for LLMs and proposed a novel taxonomy and evaluation framework. Existing methods were categorized into four classes tailored to LLM characteristics: data transformation, parameter fine-tuning, architecture design, and integrated training paradigms. The core mechanisms of these methods, covering reverse fine-tuning, parameter correction, architecture restructuring and privacy-aware training, were outlined. This paper constructed an evaluation framework based on unlearning completeness, utility preservation, and computational and communication overhead, enabling a comparative analysis of the strengths and applicability boundaries of each approach. Finally, within application scenarios such as federated learning and online services, unified formal definitions, verifiable unlearning, and support for streaming deletion remain critical open challenges.

Foundation Support

黑龙江省省属本科高校优秀青年教师基础研究支持计划(YQJH2024239)
黑龙江省自然科学基金联合基金培育项目(PL2024F002)
国家外国专家重点支撑项目(D20250185)
黑龙江省基本科研业务费基础研究项目(2019-KYYWF-1386)

Publish Information

DOI: 10.19734/j.issn.1001-3695.2025.12.0482
Publish at: Application Research of Computers Accepted Paper, Vol. 43, 2026 No. 7

Publish History

[2026-03-24] Accepted Paper

Cite This Article

张磊, 张强, 乔俊钊, 等. 基于大模型遗忘的隐私保护:方法、评估与挑战 [J]. 计算机应用研究, 2026, 43 (7). (2026-03-24). https://doi.org/10.19734/j.issn.1001-3695.2025.12.0482. (Zhang Lei, Zhang Qiang, Qiao Junzhao, et al. Privacy protection via large language model unlearning: methods, evaluation, and challenges [J]. Application Research of Computers, 2026, 43 (7). (2026-03-24). https://doi.org/10.19734/j.issn.1001-3695.2025.12.0482. )

About the Journal

  • Application Research of Computers Monthly Journal
  • Journal ID ISSN 1001-3695
    CN  51-1196/TP

Application Research of Computers, founded in 1984, is an academic journal of computing technology sponsored by Sichuan Institute of Computer Sciences under the Science and Technology Department of Sichuan Province.

Aiming at the urgently needed cutting-edge technology in this discipline, Application Research of Computers reflects the mainstream technology, hot technology and the latest development trend of computer application research at home and abroad in a timely manner. The main contents of the journal include high-level academic papers in this discipline, the latest scientific research results and major application results. The contents of the columns involve new theories of computer discipline, basic computer theory, algorithm theory research, algorithm design and analysis, blockchain technology, system software and software engineering technology, pattern recognition and artificial intelligence, architecture, advanced computing, parallel processing, database technology, computer network and communication technology, information security technology, computer image graphics and its latest hot application technology.

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