Leveled Multikey FHE with constant-size ciphertexts from RLWE

Vanesa Daza; Paz Morillo; Sergi Rovira

Paper 2022/447

Leveled Multikey FHE with constant-size ciphertexts from RLWE

Vanesa Daza, Paz Morillo, and Sergi Rovira

Abstract

A multi-key fully homomorphic encryption (MKFHE) scheme allows a public server to evaluate arbitrary circuits over ciphertexts encrypted under different keys. One of the main drawbacks of MKFHE schemes is the need for a ciphertext expansion procedure prior to evaluation, which combines ciphertexts encrypted under different keys to a (much larger) ciphertext encrypted under a concatenated key. In this paper, we present a new (leveled) RLWE-based MKFHE scheme without ciphertext expansion.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Preprint. MINOR revision.
Keywords: Multi-key fully homomorphic encryption Ring learning with errors Party- independent ciphertexts
Contact author(s): sergi rovira @ upf edu
vanesa daza @ upf edu
paz morillo @ upc edu
History: 2022-04-12: received
Short URL: https://ia.cr/2022/447
License: CC BY

BibTeX

@misc{cryptoeprint:2022/447,
      author = {Vanesa Daza and Paz Morillo and Sergi Rovira},
      title = {Leveled Multikey FHE with constant-size ciphertexts from RLWE},
      howpublished = {Cryptology ePrint Archive, Paper 2022/447},
      year = {2022},
      note = {\url{https://eprint.iacr.org/2022/447}},
      url = {https://eprint.iacr.org/2022/447}
}