TOFU

ATWU: Token-level importance learning improves LLM unlearning via retain-conflict criterion

This paper introduces Alternating Token-Weighted Unlearning (ATWU), a framework that learns which tokens in a forget sample are most relevant to unlearning by characterizing their conflict with the retain objective. Rather than relying on auxiliary models or heuristics, ATWU jointly learns token forget-specificity and model parameters using a lightweight linear scorer over hidden states. Evaluated on TOFU and RWKU benchmarks, ATWU achieves state-of-the-art forget-retain trade-offs and produces token-level scores that align with ground-truth forget-specific spans.