Towards round-optimal secure multiparty computations: Multikey FHE without a CRS

Eunkyung Kim, Hyang Sook Lee, Jeongeun Park

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

21 Scopus citations


Multikey fully homomorphic encryption (MFHE) allows homomorphic operations between ciphertexts encrypted under different keys. In applications for secure multiparty computation (MPC) protocols, MFHE can be more advantageous than usual fully homomorphic encryption (FHE) since users do not need to agree with a common public key before the computation when using MFHE. In EUROCRYPT 2016, Mukherjee and Wichs constructed a secure MPC protocol in only two rounds via MFHE which deals with a common random/reference string (CRS) in key generation. After then, Brakerski et al. replaced the role of CRS with the distributed setup for CRS calculation to form a four round secure MPC protocol. Thus, recent improvements in round complexity of MPC protocols have been made using MFHE. In this paper, we go further to obtain round-efficient and secure MPC protocols. The underlying MFHE schemes in previous works still involve the common value, CRS, it seems to weaken the power of using MFHE to allow users to independently generate their own keys. Therefore, we resolve the issue by constructing an MFHE scheme without CRS based on LWE assumption, and then we obtain a secure MPC protocol against semi-malicious security in three rounds.

Original languageEnglish
Title of host publicationInformation Security and Privacy - 23rd Australasian Conference, ACISP 2018, Proceedings
EditorsWilly Susilo, Guomin Yang
PublisherSpringer Verlag
Number of pages13
ISBN (Print)9783319936376
StatePublished - 2018
Event23rd Australasian Conference on Information Security and Privacy, ACISP 2018 - Wollongong, Australia
Duration: 11 Jul 201813 Jul 2018

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume10946 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference23rd Australasian Conference on Information Security and Privacy, ACISP 2018

Bibliographical note

Funding Information:
Acknowledgement. The authors were supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (Grant Number: 2015R1A2A1A15054564)

Publisher Copyright:
© Springer International Publishing AG, part of Springer Nature 2018.


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