Multiparty computation with low communication, computation and interaction via threshold FHE

Gilad Asharov, Abhishek Jain, Adriana López-Alt, Eran Tromer, Vinod Vaikuntanathan, Daniel Wichs

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

240 Scopus citations

Abstract

Fully homomorphic encryption (FHE) enables secure computation over the encrypted data of a single party. We explore how to extend this to multiple parties, using threshold fully homomorphic encryption (TFHE). In such scheme, the parties jointly generate a common FHE public key along with a secret key that is shared among them; they can later cooperatively decrypt ciphertexts without learning anything but the plaintext. We show how to instantiate this approach efficiently, by extending the recent FHE schemes of Brakerski, Gentry and Vaikuntanathan (CRYPTO '11, FOCS '11, ITCS '12) based on the (ring) learning with errors assumption. Our main tool is to exploit the property that such schemes are additively homomorphic over their keys. Using TFHE, we construct simple multiparty computation protocols secure against fully malicious attackers, tolerating any number of corruptions, and providing security in the universal composability framework. Our protocols have the following properties: Low interaction: 3 rounds of interaction given a common random string, or 2 rounds with a public-key infrastructure. Low communication : independent of the function being computed (proportional to just input and output sizes). Cloud-assisted computation: the bulk of the computation can be efficiently outsourced to an external entity (e.g. a cloud service) so that the computation of all other parties is independent of the complexity of the evaluated function.

Original languageEnglish
Title of host publicationAdvances in Cryptology, EUROCRYPT 2012 - 31st Annual International Conference on the Theory and Applications of Cryptographic Techniques, Proceedings
PublisherSpringer Verlag
Pages483-501
Number of pages19
ISBN (Print)9783642290107
DOIs
StatePublished - 2012
Event31st Annual International Conference on the Theory and Applications of Cryptographic Techniques, EUROCRYPT 2012 - Cambridge, United Kingdom
Duration: 15 Apr 201219 Apr 2012

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume7237 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

Conference31st Annual International Conference on the Theory and Applications of Cryptographic Techniques, EUROCRYPT 2012
Country/TerritoryUnited Kingdom
CityCambridge
Period15/04/1219/04/12

Bibliographical note

Place of conference:Cambridge, UK

Funding

FundersFunder number
Seventh Framework Programme239868

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