Paper 2024/1023

Constant-Size Unbounded Multi-Hop Fully Homomorphic Proxy Re-Encryption from Lattices

Feixiang Zhao
Huaxiong Wang, Nanyang Technological University
Jian Weng, Jinan University
Abstract

Proxy re-encryption is a cryptosystem that achieves efficient encrypted data sharing by allowing a proxy to transform a ciphertext encrypted under one key into another ciphertext under a different key. Homomorphic proxy re-encryption (HPRE) extends this concept by integrating homomorphic encryption, allowing not only the sharing of encrypted data but also the homomorphic computations on such data. The existing HPRE schemes, however, are limited to a single or bounded number of hops of ciphertext re-encryptions. To address this limitation, this paper introduces a novel lattice-based, unbounded multi-hop fully homomorphic proxy re-encryption (FHPRE) scheme, with constant-size ciphertexts. Our FHPRE scheme supports an unbounded number of reencryption operations and enables arbitrary homomorphic computations over original, re-encrypted, and evaluated ciphertexts. Additionally, we propose a potential application of our FHPRE scheme in the form of a non-interactive, constant-size multi-user computation system for cloud computing environments.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Published elsewhere. Minor revision. ESORICS 2024
Keywords
Proxy re-encryptionFully homomorphic encryptionUnbounded multi-hopBootstrappingLattice-based cryptography
Contact author(s)
fxzhao37 @ gmail com
hxwang @ ntu edu sg
cryptjweng @ gmail com
History
2024-06-28: approved
2024-06-25: received
See all versions
Short URL
https://ia.cr/2024/1023
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2024/1023,
      author = {Feixiang Zhao and Huaxiong Wang and Jian Weng},
      title = {Constant-Size Unbounded Multi-Hop Fully Homomorphic Proxy Re-Encryption from Lattices},
      howpublished = {Cryptology {ePrint} Archive, Paper 2024/1023},
      year = {2024},
      url = {https://eprint.iacr.org/2024/1023}
}
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