LoTUS: Large-Scale Machine Unlearning with a Taste of Uncertainty

We present LoTUS, a novel Machine Unlearning (MU) method that eliminates the influence of training samples from pre-trained models, avoiding retraining from scratch. LoTUS smooths the prediction probabilities of the model up to an information-theoretic bound, mitigating its over-confidence stemming from data memorization. We evaluate LoTUS on Transformer and ResNet18 models against eight baselines across five public datasets. Beyond established MU benchmarks, we evaluate unlearning on ImageNet1k, a large-scale dataset, where retraining is impractical, simulating real-world conditions. Moreover, we introduce the novel Retrain-Free Jensen-Shannon Divergence (RF-JSD) metric to enable evaluation under real-world conditions. The experimental results show that LoTUS outperforms state-of-the-art methods in terms of both efficiency and effectiveness. Code:this https URL.

@article{spartalis2025_2503.18314,
  title={ LoTUS: Large-Scale Machine Unlearning with a Taste of Uncertainty },
  author={ Christoforos N. Spartalis and Theodoros Semertzidis and Efstratios Gavves and Petros Daras },
  journal={arXiv preprint arXiv:2503.18314},
  year={ 2025 }
}