University of Waterloo
The retrieval of information from a remote database server typically demands providing the server with some search terms to assist with the retrieval task. However, keeping the search terms private without undermining the server's ability to retrieve the information is desirable for many privacy-preserving systems. Private Information Retrieval (PIR) provides a cryptographic means for retrieving data from a database without the database or database administrator learning any information about which particular item was retrieved. A study of the computational practicality of PIR by Sion and Carbunar in 2007 concluded that no existing construction is as efficient as the trivial PIR scheme - the server transferring its entire database to the client.