Profile-DP: Differential Privacy for User-Controlled Profile Release in Personalized LLM Inference

Summary

Profile-DP is a policy-aware local differential privacy framework for releasing user profiles in personalized LLM inference, bounding the release of facts users withhold while treating public instructions, profile schemas and authorized facts as public side information. Its two finite-domain mechanisms, DP-SLOT and DP-BLOCK, are evaluated on PEEP, where DP-BLOCK leads the utility composite at all 13 structured budgets and is closest to the ideal privacy-utility point in 18 of 26 format-budget settings. DP-BLOCK discloses less, while DP-SLOT retains more authorized facts.