Advertisement

Journal of Cryptology

, Volume 16, Issue 4, pp 219–237 | Cite as

Oblivious Transfers and Privacy Amplification

  • Gilles Brassard
  • Claude Crépeau
  • Stefan Wolf
Article

Abstract

Oblivious transfer (OT) is an important primitive in cryptography. In chosen one-out-of-two string OT, a sender offers two strings, one of which the other party, called the receiver, can choose to read, not learning any information about the other string. The sender on the other hand does not obtain any information about the receiver’s choice. We consider the problem of reducing this primitive to OT for single bits. Previous attempts to doing this were based on self-intersecting codes. We present a new technique for the same task, based on so-called privacy amplification. It is shown that our method has two important advantages over the previous approaches. First, it is more efficient in terms of the number of required realizations of bit OT, and second, the technique even allows for reducing string OT to (apparently) much weaker primitives. An example of such a primitive is universal OT, where the receiver can adaptively choose what type of information he wants to obtain about the two bits sent by the sender subject to the only constraint that some, possibly very small, uncertainty must remain about the pair of bits.

Information-theoretic security Oblivious transfer Universal oblivious transfer Reduction among information-theoretic primitives Privacy amplification 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© International Association for Cryptological Research 2003

Authors and Affiliations

  1. 1.Département IRO, Université de Montréal, C.P. 6128, succursale centre-ville, Montréal, Québec, H3C 3J7Canada
  2. 2.School of Computer Science, McGill University, room 318, 3480 rue University, Montréal, Québec, H3A 2A7Canada
  3. 3.Département IRO, Université de Montréal, C.P. 6128, succursale centre-ville, Montréal, Québec, H3C 3J7Canada

Personalised recommendations