Revisiting Lattice-based Blind Signatures Again

Yi-Fu Lai; Yu Yu

Paper 2026/2402

Revisiting Lattice-based Blind Signatures Again

Yi-Fu Lai

, Shanghai Jiao Tong University

Yu Yu

, Shanghai Jiao Tong University

Abstract

We show an attack on a lattice-based blind signature proposed in Crypto'20. Formally it is a linear hash function based framework with a lattice-based instantiation. We first notice a bug in their security proof of blindness, which is overlooked these years. Then, we develop an attack under the honest key and the honest-but-curious signer setting against the blindness notion of the schemes by exploiting the coorelations between the leaves of the tree. We also discuss how to repair the scheme.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Preprint.
Keywords: lattice cryptography blind signatures cryptoanalysis
Contact author(s): yifu lai @ sjtu edu cn
yyuu @ sjtu edu cn
History: 2026-10-08: approved; 2026-10-07: received; See all versions
Short URL: https://ia.cr/2026/2402
License: CC BY

BibTeX

@misc{cryptoeprint:2026/2402,
      author = {Yi-Fu Lai and Yu Yu},
      title = {Revisiting Lattice-based Blind Signatures Again},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/2402},
      year = {2026},
      url = {https://eprint.iacr.org/2026/2402}
}