Maliciously circuit-private FHE

Rafail Ostrovsky, Anat Paskin-Cherniavsky, Beni Paskin-Cherniavsky

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

30 Scopus citations


We present a framework for transforming FHE (fully homomorphic encryption) schemes with no circuit privacy requirements into maliciously circuit-private FHE. That is, even if both maliciously formed public key and ciphertext are used, encrypted outputs only reveal the evaluation of the circuit on some well-formed input x*. Previous literature on FHE only considered semi-honest circuit privacy. Circuit-private FHE schemes have direct applications to computing on encrypted data. In that setting, one party (a receiver) holding an input x wishes to learn the evaluation of a circuit C held by another party (a sender). The goal is to make receiver's work sublinear (and ideally independent) of |C|, using a 2-message protocol. The transformation technique may be of independent interest, and have various additional applications. The framework uses techniques akin to Gentry's bootstrapping and conditional disclosure of secrets (CDS [AIR01]) combining a non circuit private FHE scheme, with a homomorphic encryption (HE) scheme for a smaller class of circuits which is maliciously circuit-private. We devise the first known circuit private FHE, by instantiating our framework by various (standard) FHE schemes from the literature.

Original languageEnglish
Title of host publicationAdvances in Cryptology, CRYPTO 2014 - 34th Annual Cryptology Conference, Proceedings
Number of pages18
EditionPART 1
StatePublished - 2014
Externally publishedYes
Event34rd Annual International Cryptology Conference, CRYPTO 2014 - Santa Barbara, CA, United States
Duration: 17 Aug 201421 Aug 2014

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
NumberPART 1
Volume8616 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference34rd Annual International Cryptology Conference, CRYPTO 2014
Country/TerritoryUnited States
CitySanta Barbara, CA


  • Fully homomorphic encryption
  • computing on encrypted data
  • malicious setting
  • privacy


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