Quantum Private Queries

Vittorio Giovannetti, Seth Lloyd, Lorenzo Maccone
2008 Physical Review Letters  
We propose a cheat sensitive quantum protocol to perform a private search on a classical database which is efficient in terms of communication complexity. It allows a user to retrieve an item from the server in possession of the database without revealing which item she retrieved: if the server tries to obtain information on the query, the person querying the database can find it out. Furthermore our protocol ensures perfect data privacy of the database, i.e. the information that the user can
more » ... trieve in a single queries is bounded and does not depend on the size of the database. With respect to the known (quantum and classical) strategies for private information retrieval, our protocol displays an exponential reduction both in communication complexity and in running-time computational complexity.
doi:10.1103/physrevlett.100.230502 pmid:18643478 fatcat:cv5irylpdrhu5dbbekiifhewz4