Paper 2023/642 Original: eprint.iacr.org/2023/642 ↗

PELTA -- Shielding Multiparty-FHE against Malicious Adversaries

Sylvain Chatel
Christian Mouchet
Ali Utkan Sahin
Apostolos Pyrgelis
Carmela Troncoso
Jean-Pierre Hubaux
Abstract

Multiparty fully homomorphic encryption (MFHE) schemes enable multiple parties to efficiently compute functions on their sensitive data while retaining confidentiality. However, existing MFHE schemes guarantee data confidentiality and the correctness of the computation result only against honest-but-curious adversaries. In this work, we provide the first practical construction that enables the verification of MFHE operations in zero-knowledge, protecting MFHE from malicious adversaries. Our solution relies on a combination of lattice-based commitment schemes and proof systems which we adapt to support both modern FHE schemes and their implementation optimizations. We implement our construction in PELTA. Our experimental evaluation shows that PELTA is one to two orders of magnitude faster than existing techniques in the literature.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Preprint.
History
2023-05-08: last updated
2023-05-05: published
Short URL
https://ia.cr/2023/642
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2023/642,
      author = {Sylvain Chatel and Christian Mouchet and Ali Utkan Sahin and Apostolos Pyrgelis and Carmela Troncoso and Jean-Pierre Hubaux},
      title = {PELTA -- Shielding Multiparty-FHE against Malicious Adversaries},
      howpublished = {Cryptology {ePrint} Archive, Paper 2023/642},
      year = {2023},
      url = {https://eprint.iacr.org/2023/642}
}
Note: In order to protect the privacy of readers, this archive does not use cookies or embedded third party content.