Paper 2024/1984

Low Communication Threshold Fully Homomorphic Encryption

Alain Passelègue, CryptoLab Inc.
Damien Stehlé, CryptoLab Inc.
Abstract

This work investigates constructions of threshold fully homomorphic encryption with low communication, i.e., with small ciphertexts and small decryption shares. In this context, we discuss in detail the technicalities for achieving full-fledged threshold FHE, and put forward limitations regarding prior works, including an attack against the recent construction of Boudgoust and Scholl [ASIACRYPT 2023]. In light of our observations, we generalize the definition of threshold fully homomorphic encryption by adding an algorithm which allows to introduce additional randomness in ciphertexts before they are decrypted by parties. In this setting, we are able to propose a construction which offers small ciphertexts and small decryption shares.

Metadata
Available format(s)
PDF
Publication info
A minor revision of an IACR publication in ASIACRYPT 2024
Keywords
Fully Homomorphic EncryptionThreshold Cryptography
Contact author(s)
alain passelegue @ cryptolab co kr
damien stehle @ cryptolab co kr
History
2024-12-12: approved
2024-12-08: received
See all versions
Short URL
https://ia.cr/2024/1984
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2024/1984,
      author = {Alain Passelègue and Damien Stehlé},
      title = {Low Communication Threshold Fully Homomorphic Encryption},
      howpublished = {Cryptology {ePrint} Archive, Paper 2024/1984},
      year = {2024},
      url = {https://eprint.iacr.org/2024/1984}
}
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