Oblivious-Transfer Amplification

JE Wullschleger

Research output: Chapter in Book/Report/Conference proceedingConference Contribution (Conference Proceeding)

45 Citations (Scopus)


Oblivious transfer (OT) is a primitive of paramount importance in cryptography or, more precisely, two- and multi-party computation due to its universality. Unfortunately, OT cannot be achieved in an unconditionally secure way for both parties from scratch. Therefore, it is a natural question what information-theoretic primitives or computational assumptions OT can be based on. The results in our paper are threefold. First, we give an optimal proof for the standard protocol to realize unconditionally secure OT from a weak variant of OT called universal OT, for which a malicious receiver can virtually obtain any possible information he wants, as long as he does not get all the information. This result is based on a novel distributed leftover hash lemma which is of independent interest. Second, we give conditions for when OT can be obtained from a faulty variant of OT called weak OT, for which it can occur that any of the parties obtains too much information, or the result is incorrect. These bounds and protocols, which correct on previous results by Damgård et. al., are of central interest since in most known realizations of OT from weak primitives, such as noisy channels, a weak OT is constructed first. Finally, we carry over our results to the computational setting and show how a weak OT that is sometimes incorrect and is only mildly secure against computationally bounded adversaries can be strengthened.
Translated title of the contributionOblivious-Transfer Amplification
Original languageEnglish
Title of host publicationAdvances in Cryptology - EUROCRYPT 2007
Subtitle of host publication26th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Barcelona, Spain, May 20-24, 2007. Proceedings
PublisherSpringer Berlin Heidelberg
Number of pages18
ISBN (Electronic)9783540725404
ISBN (Print)9783540725398
Publication statusPublished - 23 Jun 2007

Publication series

NameLecture Notes in Computer Science
PublisherSpringer Berlin Heidelberg

Bibliographical note

Editors: Moni Naor
ISBN: 9783540725398
Publisher: Springer
Name and Venue of Conference: Advances in Cryptology - EUROCRYPT 2007: 26th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Barcelona, Spain, May 20-24, 2007
Conference Organiser: Moni Naor


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