A Survey on Private Information Retrieval

Abstract

Alice wants to query a database but she does not want the database to learn what she isquerying. She can ask for the entire database. Can she get her query answered with less communication? One model of this problem is Private Information Retrieval, henceforth PIR. We survey results obtained about the PIR model including partial answers to the following questions. (1) What if there are k non-communicating copies of the database but they are computationally unbounded? (2) What if there is only one copy of the database and it is computationally bounded?