arXiv AI

Safety Alignment via Constrained Knowledge Unlearning

The paper introduces Constrained Knowledge Unlearning (CKU), a safety alignment method that selectively prunes gradients of neurons in specific MLP layers to delete harmful knowledge while preserving useful information. CKU identifies a subset of neurons associated with valuable knowledge and protects them during the unlearning process, thereby mitigating jailbreak attacks. Experiments show that CKU improves model safety without sacrificing overall performance, and the study also offers insights into neuron knowledge sensitivity across MLP layers.

arXiv AI
1d ago

Addition by Subtraction: Toward Mitigating Fragile Safety Alignment in Large Language Models

The paper introduces a method called Addition by Subtraction to strengthen safety alignment in large language models. By gradually removing identified safety‑critical neurons during finetuning and re‑optimizing preferences, the authors reduce the model’s reliance on sparse components that can be targeted by pruning or ablation attacks. Experiments on four models from three vendors show that this approach improves robustness to both white‑box and black‑box jailbreaks, lowers attack success rates by up to 90%, and enhances truthfulness while preserving general capabilities.

By Hamid Dashtbani, Alexandra Dmitrienko
arXiv AI
Aug 26

NeuronGuard: Robust LLM Safety Alignment via Ablation-Aware Safety Signal Redistribution

NeuronGuard is a fine‑tuning defense for large language models that hardens them against both jailbreak and neuron‑level attacks. It redistributes safety signals across many neurons by identifying safety‑critical ones with per‑layer linear classifiers, enforcing refusal behavior when those neurons are ablated, and applying KL‑divergence regularization for consistency. A randomized gradient projection preserves task performance, and the authors provide a formal guarantee that NeuronGuard lowers the attack success rate upper bound, with experiments showing near‑zero success rates across multiple models and attack strategies.

By Anjun Gao, Yueyang Quan, Yufei Xia, Zhuqing Liu, Minghong Fang
arXiv AI
Oct 1

Faithful Dual-constrained Erasure for Robust LLM Safety Alignment

The paper introduces FDCU, a dual‑constrained subspace projection framework designed to improve machine unlearning for large language models. FDCU limits parameter updates with a dual‑masking rule that preserves general knowledge via Fisher Information while preventing the activation of spurious suppressors through the Principle of Minimal Functional Intervention. Experiments show that FDCU achieves state‑of‑the‑art robustness against retraining attacks while maintaining near‑lossless general utility, thereby ensuring durable safety for LLMs.

By Jiaqing Li, Shide Zhou, Zhibo Zhang, Yuxi Li, Tianlong Yu, Kailong Wang