Discretization Error Reduction for High Precision Torus Fully Homomorphic Encryption

Kang Hoon Lee, Ji Won Yoon

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

In recent history of fully homomorphic encryption, bootstrapping has been actively studied throughout many HE schemes. As bootstrapping is an essential process to transform somewhat homomorphic encryption schemes into fully homomorphic, enhancing its performance is one of the key factors of improving the utility of homomorphic encryption. In this paper, we propose an extended bootstrapping for TFHE, which we name it by EBS. One of the main drawback of TFHE bootstrapping was that the precision of bootstrapping is mainly decided by the polynomial dimension N. Thus if one wants to bootstrap with high precision, one must enlarge N, or take alternative method. Our EBS enables to use small N for parameter selection, but to bootstrap in higher dimension to keep high precision. Moreover, it can be easily parallelized for faster computation. Also, the EBS can be easily adapted to other known variants of TFHE bootstrappings based on the original bootstrapping algorithm. We implement our EBS along with the full domain bootstrapping methods known (FDFB, TOTA, Comp ), and show how much our EBS can improve the precision for those bootstrapping methods. We provide experimental results and thorough analysis with our EBS, and show that EBS is capable of bootstrapping with high precision even with small N, thus small key size, and small complexity than selecting large N by birth.

Original languageEnglish
Title of host publicationPublic-Key Cryptography – PKC 2023 - 26th IACR International Conference on Practice and Theory of Public-Key Cryptography, Proceedings
EditorsAlexandra Boldyreva, Vladimir Kolesnikov
PublisherSpringer Science and Business Media Deutschland GmbH
Pages33-62
Number of pages30
ISBN (Print)9783031313707
DOIs
Publication statusPublished - 2023
Event26th IACR International Conference on Practice and Theory of Public-Key Cryptography, PKC 2023 - Atlanta, United States
Duration: 2023 May 72023 May 10

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume13941 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

Conference26th IACR International Conference on Practice and Theory of Public-Key Cryptography, PKC 2023
Country/TerritoryUnited States
CityAtlanta
Period23/5/723/5/10

Bibliographical note

Publisher Copyright:
© 2023, International Association for Cryptologic Research.

Keywords

  • Homomorphic encryption
  • Precision
  • TFHE

ASJC Scopus subject areas

  • Theoretical Computer Science
  • General Computer Science

Fingerprint

Dive into the research topics of 'Discretization Error Reduction for High Precision Torus Fully Homomorphic Encryption'. Together they form a unique fingerprint.

Cite this