A Novel Tamper Evident Single Database Information-Theoretic Private Information Retrieval for User Privacy Applications

Providing perfect privacy to the user against analytics enabled trusted-but-curious type of database server during private information retrieval has gained major attention. The major problem with the existing user privacy preserving information retrieval methods is that either server has adopted its own privacy preserving policy (i.e., user privacy is guaranteed through the server privacy policy) or user has conveyed to use intractability assumption based user privacy preserving techniques. Due to this, user privacy is not completely assured till date. We have successfully constructed a perfect user privacy preserving information retrieval scheme in a single database setting called sitPIR using the concept of Private Information Retrieval (PIR). In the proposed scheme, the identically distributed \(\mathcal {O}\)(5 log N) bits query exhibit perfect privacy where N is the RSA composite. Note that the proposed scheme preserves user privacy (i.e., user interest) using an information-theoretic query against the curious server and preserves data privacy through \(\mathcal {O}(o(n)+ 2\text { log }N)\) response bits against computationally bounded intermediate adversary using Quadratic Residuosity Assumption (QRA) where n is the database size. We have also extended the proposed scheme to a tamper-evident single database information-theoretic Private Block Retrieval (PBR) scheme called sitPBR.