PILLAR: Private Inverted-Index Lexical Lookup for Augmented Retrieval.

arXiv:2609.36326v2 Announce Type: replace Abstract: Retrieval-augmented generation (RAG) hands the user's query to whoever hosts the corpus. We propose PILLAR, a Privacy-Preserving RAG (PPRAG) system based on Private Information Retrieval (PIR) in which a clie