On the Security of Multikey Homomorphic Encryption

Hyang Sook Lee, Jeongeun Park

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

5 Scopus citations


Multikey fully homomorphic encryption (MFHE) scheme enables homomorphic computation on data encrypted under different keys. To decrypt a result ciphertext, all the involved secret keys are required. For multi decryptor setting, decryption is a protocol with minimal interaction among parties. However, all prior schemes supporting the protocol are not secure in public channel against a passive external adversary who can see any public information not joining the protocol. Furthermore, the possible adversaries have not been defined clearly. In this paper, we revisit the security of MFHE and present a secure one-round decryption protocol. We apply it to one of existing schemes and prove the scheme is secure against possible static adversaries. As an application, we construct a two round multiparty computation without common random string.

Original languageEnglish
Title of host publicationCryptography and Coding - 17th IMA International Conference, IMACC 2019, Proceedings
EditorsMartin Albrecht
Number of pages16
ISBN (Print)9783030351984
StatePublished - 2019
Event17th IMA International Conference on Cryptography and Coding, IMACC 2019 - Oxford, United Kingdom
Duration: 16 Dec 201918 Dec 2019

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume11929 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference17th IMA International Conference on Cryptography and Coding, IMACC 2019
Country/TerritoryUnited Kingdom

Bibliographical note

Publisher Copyright:
© 2019, Springer Nature Switzerland AG.


  • MPC without CRS
  • Multikey homomorphic encryption
  • Security of MFHE


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