Paper 2026/387

A Comprehensive Break of the Tropical Matrix-Based Signature Scheme

Sopan Chavhan, Department of Mathematics, Shri Vyankatesh Arts, Commerce and Science College, Deulgaon Raja, Buldhana, 443204, Maharashtra, India.
Shrikant Chaudhari, School of Mathematical Sciences, K.B.C. North Maharashtra University, Umavi Nagar, Jalgaon, 425001, Maharashtra, India.
Abstract

In the recent preprint [GMS26], Grigoriev, Monico and Shpilrain proposed a digital signature protocol based on matrices over the tropical integer semiring. we show that the scheme can be completely broken. We present a chosen‑hash forgery, a malleability attack that breaks strong unforgeability, and an SMT‑based key recovery attack demonstrating that a single valid signature together with the public key suffices to recover a full private key in within one second for the recommended parameters. Our attacks exploit algebraic properties of the signing equations rather than the claimed NP‑hard problem. Independent work by Sferlazza concurrently identified related vulnerabilities.

Metadata
Available format(s)
PDF
Category
Attacks and cryptanalysis
Publication info
Preprint.
Keywords
digital signaturetropical semiringcryptanalysismatrix factorizationmalleabilitySMT solving
Contact author(s)
sjchavhanmath17 @ gmail com
drsrchaudhari @ nmu ac in
History
2026-03-15: revised
2026-02-25: received
See all versions
Short URL
https://ia.cr/2026/387
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2026/387,
      author = {Sopan Chavhan and Shrikant Chaudhari},
      title = {A Comprehensive Break of the Tropical Matrix-Based Signature Scheme},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/387},
      year = {2026},
      url = {https://eprint.iacr.org/2026/387}
}
Note: In order to protect the privacy of readers, eprint.iacr.org does not use cookies or embedded third party content.