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MSc Research Project — 2025

Unlearning Identity Information in Latent Diffusion Models

Development of a concept editing method to prevent identity reproduction in the Arc2Face model by targeting key–value representations in cross-attention layers.

Machine Unlearning Diffusion Models Cross-Attention Privacy

Overview

This research focuses on developing techniques to remove specific identity reproduction capability from latent diffusion models while preserving their general image generation capabilities. The approach targets the StableDiffusions-based Arc2Face model, which specializes in face generation from SoTA ArcFace identity embeddings.

Methodology

Our approach focuses on the cross-attention layers of the diffusion model, specifically targeting the key–value representations that encode identity information. By selectively modifying these representations, we aim to prevent the model from reproducing specific identities.

Full details of the methodology will be disclosed after publication.

Cross-Attention Mechanism Diagram

Figure 1: Cross-attention mechanism in diffusion models

Experimental Results

Below are detailed visualizations showing the unlearning progression across different experiments. Each experiment demonstrates how the model progressively "forgets" the target identity while maintaining its ability to generate other faces through anchor pull, and keeps retain identities consistent.

Experiment: Identity 65

Parameters: lr=2e-05, preservation_weight=15.0, neg_guidance=1.0

Forget Progression

ID 65 Baseline

Baseline

ID 65 Step 60

Step 60

ID 65 Step 180

Step 180

ID 65 Step 240

Step 240

ID 65 Step 300

Step 300

Anchor

ID 65 Anchor

Anchor

Retain Progression (Identity 14692)

Retain 14692 Step 60

Step 60

Retain 14692 Step 180

Step 180

Retain 14692 Step 300

Step 300

Experiment: Identity 378

Parameters: lr=5e-05, preservation_weight=35.0, neg_guidance=1.0

Forget Progression

ID 378 Baseline

Baseline

ID 378 Step 60

Step 60

ID 378 Step 180

Step 180

ID 378 Step 240

Step 240

ID 378 Step 300

Step 300

Anchor

ID 378 Anchor

Anchor

Retain Progression (Identity 14692)

Retain 14692 Step 60

Step 60

Retain 14692 Step 180

Step 180

Retain 14692 Step 300

Step 300

Experiment: Identity 698

Parameters: lr=5e-05, preservation_weight=20.0, neg_guidance=1.0

Forget Progression

ID 698 Baseline

Baseline

ID 698 Step 60

Step 60

ID 698 Step 180

Step 180

ID 698 Step 240

Step 240

ID 698 Step 300

Step 300

Anchor

ID 698 Anchor

Anchor

Retain Progression (Identity 11102)

Retain 11102 Step 60

Step 60

Retain 11102 Step 180

Step 180

Retain 11102 Step 300

Step 300

References

[1] Papantoniou, F. P., Lattas, A., Moschoglou, S., Deng, J., Kainz, B., & Zafeiriou, S. (2024). Arc2Face: A Foundation Model for ID-Consistent Human Faces. European Conference on Computer Vision (ECCV), pp. 241-261. arXiv:2403.11641

[2] Deng, J., Guo, J., Yang, J., Xue, N., Kotsia, I., & Zafeiriou, S. (2022). ArcFace: Additive Angular Margin Loss for Deep Face Recognition. IEEE Transactions on Pattern Analysis and Machine Intelligence, 44(10), 5962-5979. DOI:10.1109/TPAMI.2021.3087709

[3] Gandikota, R., Materzynska, J., Fiotto-Kaufman, J., & Bau, D. (2023). Erasing Concepts from Diffusion Models. arXiv:2303.07345

[4] Ruiz, N., Li, Y., Jampani, V., Pritch, Y., Rubinstein, M., & Aberman, K. (2023). DreamBooth: Fine Tuning Text-to-Image Diffusion Models for Subject-Driven Generation. arXiv:2208.12242

Ongoing Work

This page will be updated as the research progresses. Check back for new results and findings.