EraseFlow: Learning Concept Erasure Policies via GFlowNet-Driven Alignment

Naga Sai Abhiram Kusumba (Capital One) · Maitreya Patel (Adobe / Arizona State University) · Kyle Min (Oracle) · Changhoon Kim (Soongsil University) · Chitta Baral (Arizona State University) · 'YZ' Yezhou Yang (Arizona State University)
concept erasuredenoising trajectoriesdiffusion-based generationempirical resultsexplorationgeneralizationgflownetshackable rewardsperformance optimizationprior preservationreward modelsstochastic policytarget conceptstext-to-image generationtrajectory-balance objectiveunlearning

Erasing harmful or proprietary concepts from powerful text‑to‑image generators is an emerging safety requirement, yet current ``concept erasure'' techniques either collapse image quality, rely on brittle adversarial losses, or demand prohibitive retraining cycles. We trace these limitations to a myopic view of the denoising trajectories that govern diffusion‑based generation. We introduce EraseFlow, the first framework that casts concept unlearning as exploration in the space of denoising paths and optimizes it with a GFlowNets equipped with the trajectory‑balance objective. By sampling entire trajectories rather than single end states, EraseFlow learns a stochastic policy that steers generation away from target concepts while preserving the model’s prior. EraseFlow eliminates the need for carefully crafted reward models and by doing this, it generalizes effectively to unseen concepts and avoids hackable rewards while improving the performance. Extensive empirical results demonstrate that EraseFlow outperforms existing baselines and achieves an optimal trade-off between performance and prior preservation.