Paper 2026/767

Cryptanalysis of the Sharafi–Daghigh digital signature scheme

Nour-eddine Rahmani, Mohammed I University
Taoufik Serraj, Mohammed I University
Abdelmalek Azizi, SupMTI
Abstract

This paper is devoted to the study of the Ring-LWE-based digital signature scheme proposed by Sharafi and Daghigh, especially, the cryptanalysis of this scheme. The Sharafi and Daghigh’s scheme is inspired by the Lindner–Peikert encryption paradigm and adopts a hash-and-sign approach via the Fiat–Shamir transformation. The security claims rely on the assumed hardness of the Ring LWE and Ring-SIS problems, whose definitions and properties are well studied in last two decades. We demonstrate that this scheme is not secure and generalise our analysis to the analogous scheme in the plain-LWE setting.

Metadata
Available format(s)
PDF
Category
Attacks and cryptanalysis
Publication info
Published elsewhere. Major revision. Moroccan Journal of Algebra and Geometry with Applications
Keywords
LWESISDigital SignatureCryptanalysisQuantum Safe
Contact author(s)
nour-eddine rahmani @ ump ac ma
t serraj @ ump ac ma
a azizi @ ump ac ma
History
2026-06-22: revised
2026-04-18: received
See all versions
Short URL
https://ia.cr/2026/767
License
Creative Commons Attribution-NonCommercial-NoDerivs
CC BY-NC-ND

BibTeX

@misc{cryptoeprint:2026/767,
      author = {Nour-eddine Rahmani and Taoufik Serraj and Abdelmalek Azizi},
      title = {Cryptanalysis of the Sharafi–Daghigh digital signature scheme},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/767},
      year = {2026},
      url = {https://eprint.iacr.org/2026/767}
}
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