Personalized frequency estimation via multi-domain utility-optimized local differential privacy
摘要
Utility-Optimized Local Differential Privacy (ULDP) improves frequency estimation utility by separating sensitive from non-sensitive values, yet a single sensitive scope limits personalization and bandwidth efficiency. We propose Multi-Domain Personalized ULDP (MDPULDP), which partitions the real sensitive domain into disjoint subdomains and lets users choose both a protected scope and a privacy budget. We aggregate heterogeneous reports via align-then-weight: per-scope debiasing, server-side alignment/lifting to the global domain, frequency-weighted averaging, and preserving unbiasedness. We instantiate MDPULDP with Generalized Randomized Response (GRR) and Randomized Aggregatable Privacy-Preserving Ordinal Response (RAPPOR). For both instantiations, we prove