Paper 2025/1907

Introducing GRAFHEN: GRoup-bAsed Fully Homomorphic Encryption without Noise

Pierre Guillot, Ravel Technology
Auguste Hoang Duc, Ravel Technology
Michel Koskas, Ravel Technology
Florian Méhats, Ravel Technology
Abstract

We present GRAFHEN, a new cryptographic scheme which offers Fully Homomorphic Encryption without the need for bootstrapping (or in other words, without noise). Building on the work of Nuida and others, we achieve this using encodings in groups. The groups are represented on a machine using rewriting systems. In this way the subgroup membership problem, which an attacker would have to solve in order to break the scheme, becomes maximally hard, while performance is preserved. In fact we include a simple benchmark demonstrating that our implementation runs several orders of magnitude faster than existing standards. We review many possible attacks against our protocol and explain how to protect the scheme in each case.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Preprint.
Keywords
Fully Homomorphic EncryptionNoisefree FHE schemeGroup-based cryptographyRewriting systems
Contact author(s)
pierre guillot @ raveltech io
auguste hoangduc @ raveltech io
michel koskas @ raveltech io
florian mehats @ raveltech io
History
2025-10-17: approved
2025-10-13: received
See all versions
Short URL
https://ia.cr/2025/1907
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2025/1907,
      author = {Pierre Guillot and Auguste Hoang Duc and Michel Koskas and Florian Méhats},
      title = {Introducing {GRAFHEN}: {GRoup}-{bAsed} Fully Homomorphic Encryption without Noise},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/1907},
      year = {2025},
      url = {https://eprint.iacr.org/2025/1907}
}
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