[DMO00] Single Database Private Information Retrieval Implies Oblivious Transfer

Authors: Giovanni Di Crescenzo, Tal Malkin, Rafail Ostrovsky | Venue: Eurocrypt 2000 | Source

Abstract

A Single-Database Private Information Retrieval (PIR) is a protocol that allows a user to privately retrieve from a database an entry with as small as possible communication complexity. We call a PIR protocol non-trivial if its total communication is strictly less than the size of the database. Non-trivial PIR is an important cryptographic primitive with many applications. Thus, understanding which assumptions are necessary for implementing such a primitive is an important task, although (so far) not a well-understood one. In this paper we show that any non-trivial PIR implies Oblivious Transfer, a far better understood primitive. Our result not only significantly clarifies our understanding of any non-trivial PIR protocol, but also yields the following consequences:

  • Any non-trivial PIR is complete for all two-party and multi-party secure computations.
  • There exists a communication-efficient reduction from any PIR protocol to a 1-out-of-n Oblivious Transfer protocol (also called SPIR).
  • There is strong evidence that the assumption of the existence of a one-way function is necessary but not sufficient for any non-trivial PIR protocol.

BibTeX

@Inproceedings{EC:DiCMalOst00,
  author = {Giovanni {Di Crescenzo} and Tal Malkin and Rafail Ostrovsky},
  title = {Single Database Private Information Retrieval Implies Oblivious Transfer},
  pages = {122--138},
  editor = {Bart Preneel},
  booktitle = {Advances in Cryptology -- {EUROCRYPT}~2000},
  volume = {1807},
  series = {Lecture Notes in Computer Science},
  address = {Bruges, Belgium},
  month = {may~14--18},
  publisher = {Springer Berlin Heidelberg, Germany},
  year = {2000},
  doi = {10.1007/3-540-45539-6_10},
}