Paper 2026/1348
On Canonical Liftings, Group Actions, and Linkable Ring Signatures
, Technology Innovation Institute, Polytechnic University of Turin, Polytechnic University of Turin, Florida Atlantic UniversityAbstract
We introduce the notion of canonical lifting for group actions. This generalises existing techniques for reducing the size of group-action-based signatures, such as the canonical forms used in the LESS signature scheme. Building on this framework, we construct Sigma protocols and a linkable ring signature scheme. Notably, our approach avoids the key-reuse mechanism for linkability used in the framework of Beullens et al. (ASIACRYPT'20), which was shown to be insecure for group actions arising from linear code equivalence (ASIACRYPT'24) and lattice isomorphism (CiC'25). The resulting signatures have size logarithmic in the ring size. We provide security proofs at the level of the abstract canonical-lifting framework, which are then inherited by concrete instantiations satisfying the required assumptions. Finally, we instantiate our approach using the linear code equivalence group action and obtain a linkable ring signature scheme CELeReS, achieving signature sizes that compare favourably with the state of the art, and our AVX2-optimised C implementation demonstrates its practical applicability.
Note: Major revision.
Metadata
- Available format(s)
-
PDF
- Category
- Public-key cryptography
- Publication info
- Preprint.
- Keywords
- Canonical LiftingGroup ActionsSigma ProtocolsLinkable Ring SignaturesLinear Code Equivalence
- Contact author(s)
-
alessandro budroni @ tii ae
giuseppe dalconzo @ polito it
leonardo errati @ polito it
epersichetti @ fau edu - History
- 2026-08-17: revised
- 2026-06-30: received
- See all versions
- Short URL
- https://ia.cr/2026/1348
- License
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CC BY-SA
BibTeX
@misc{cryptoeprint:2026/1348,
author = {Alessandro Budroni and Giuseppe D'Alconzo and Leonardo Errati and Edoardo Persichetti},
title = {On Canonical Liftings, Group Actions, and Linkable Ring Signatures},
howpublished = {Cryptology {ePrint} Archive, Paper 2026/1348},
year = {2026},
url = {https://eprint.iacr.org/2026/1348}
}
