1998/11/01 by Benny Chor, Eyal Kushilevitz, Oded Goldreich +1 · 3 citations
Computer Science · #Complexity and Algorithms in Graphs #Computer science #Computer security #Cryptography and Data Security #Database #Database design #Database server #Database testing #Identity (music) #Information retrieval #Privacy-Preserving Technologies in Data #Private information retrieval #Scheme (mathematics) #View
paper · pdf · doi:10.1145/293347.293350
openalex publication_date 1998/11/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Publicly accessible databases are an indispensable resource for retrieving up-to-date information. But they also pose a significant risk to the privacy of the user, since a curious database operator can follow the user's queries and infer what the user is after. Indeed, in cases where the users' intentions are to be kept secret, users are often cautious about accessing the database. It can be shown that when accessing a single database, to completely guarantee the privacy of the user, the whole database should be down-loaded; namely n bits should be communicated (where n is the number of bits in the database). In this work, we investigate whether by replicating the database, more efficient solutions to the private retrieval problem can be obtained. We describe schemes that enable a user to access k replicated copies of a database ( k ≥2) and privately retrieve information stored in the database. This means that each individual server (holding a replicated copy of the database) gets no information on the identity of the item retrieved by the user. Our schemes use the replication to gain substantial saving. In particular, we present a two-server scheme with communication complexity O(n 1/3 ).