Paper 2025/1609
Many-time Linkable Ring Signatures
Abstract
Linkable ring signatures (Liu et al., ACISP'04) is a ring signature scheme with a linking mechanism for detecting signatures from the same signer. This functionality has found many practical applications in electronic voting, cryptocurrencies, and whistleblowing systems. However, existing linkable ring signature schemes impose a fundamental limitation: users can issue only one signature, and after that their anonymity is not guaranteed. This limited number of usage is inadequate for many real-world scenarios. This work introduces the notion of Many-time Linkable Ring Signatures, extending the anonymity guarantees of standard linkable ring signatures. Specifically, many-time linkable ring signatures ensure that signers remain anonymous as long as the number of their signatures is smaller than a system-global threshold. Only when a signer exceeds this threshold the anonymity is lost. We formalize this via a security notion called T-anonymity, which guarantees that adversaries cannot distinguish signatures from users who have each produced at most T signatures. This new notion of anonymity generalizes one-time anonymity in previous linkable schemes, while providing stronger guarantees than existing constructions. We also present a lattice-based construction with proven security in the quantum random oracle model (QROM).
Note: Added a discussion about a related work (eprint 2025/243).
Metadata
- Available format(s)
-
PDF
- Category
- Public-key cryptography
- Publication info
- Published elsewhere. Major revision. ProvSec 2025
- Contact author(s)
-
ndt141 @ uowmail edu au
khoa @ uow edu au
Dongxi Liu @ data61 csiro au
Josef Pieprzyk @ data61 csiro au
wsusilo @ uow edu au - History
- 2025-09-19: revised
- 2025-09-08: received
- See all versions
- Short URL
- https://ia.cr/2025/1609
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2025/1609,
author = {Nam Tran and Khoa Nguyen and Dongxi Liu and Josef Pieprzyk and Willy Susilo},
title = {Many-time Linkable Ring Signatures},
howpublished = {Cryptology {ePrint} Archive, Paper 2025/1609},
year = {2025},
url = {https://eprint.iacr.org/2025/1609}
}