Private Proximity Retrieval Codes

A private proximity retrieval ( xmlns:xlink="http://www.w3.org/1999/xlink">PPR ) scheme is a protocol which allows user to retrieve the identities of all records in database that are within some distance $r$ from user’s record notation="LaTeX">$x$ . The xmlns:xlink="http://www.w3.org/1999/xlink">privacy at each server given by fraction kept private. In this paper, research initiated and protocols offer trade-offs between privacy, computational complexity, storage studied. particular, we assume stores copy study required minimum number servers our provides privacy level. Each receives query set queries forms code. main focus paper dedicated studying family codes generated queries. These will be shown satisfy specific covering property called retrieval intersection codes since every codeword, goal minimize codewords such code protocol. closely related known as xmlns:xlink="http://www.w3.org/1999/xlink">covering designs We introduce several lower bounds on sizes well constructions. This work focuses case when binary vectors together with Hamming distance. Other metrics Johnson metric also investigated.