Paper 2026/290 Original: eprint.iacr.org/2026/290 ↗
Improved Cryptanalysis of HFERP
Abstract
In this paper we introduce a new attack on the multivariate encryption scheme HFERP, a big field scheme including an extra variable set, additional equations of the UOV or Rainbow shape as well as addi- tional random polynomials. Our attack brings several parameter sets well below their claimed security levels. The attack combines novel methods applicable to multivariate schemes with multiple equation types with in- sights from the Simple Attack that broke Rainbow in early 2022, though interestingly the technique is applied in an orthogonal way. In addition to this attack, we apply support minors techniques on a MinRank instance drawing coefficients from the big field, which was effective against other multivariate big field schemes. This work demonstrates that there exist previously unknown impacts of the above works well beyond the scope in which they were derived.
Metadata
- Available format(s)
PDF- Category
- Attacks and cryptanalysis
- Publication info
- Preprint.
- History
- 2026-02-17: last updated
- 2026-02-17: published
- Short URL
- https://ia.cr/2026/290
- License
- https://creativecommons.org/publicdomain/zero/1.0/
BibTeX
@misc{cryptoeprint:2026/290,
author = {Max Cartor and Ryann Cartor and Hiroki Furue and Daniel Smith-Tone},
title = {Improved Cryptanalysis of HFERP},
howpublished = {Cryptology {ePrint} Archive, Paper 2026/290},
year = {2026},
url = {https://eprint.iacr.org/2026/290}
}