Cryptanalysis of a multivariate CCZ scheme

Alessio Caminata; Elisa Gorla; Madison Mabe; Martina Vigorito; Irene Villa

Paper 2025/1329 Original: eprint.iacr.org/2025/1329 ↗

Cryptanalysis of a multivariate CCZ scheme

Alessio Caminata

Elisa Gorla

Madison Mabe

Martina Vigorito

Irene Villa

Abstract

We consider the multivariate scheme $\texttt{Pesto}$, which was introduced by Calderini, Caminata, and Villa. In this scheme, the public polynomials are obtained by applying a CCZ transformation to a set of quadratic secret polynomials. As a consequence, the public key consists of polynomials of degree $4$. In this work, we show that the public degree $4$ polynomial system can be efficiently reduced to a system of quadratic polynomials. This seems to suggest that the CCZ transformation may not offer a significant increase in security, contrary to what was initially believed.

Metadata

Available format(s): PDF
Category: Attacks and cryptanalysis
Publication info: Preprint.
History: 2025-07-21: last updated; 2025-07-21: published
Short URL: https://ia.cr/2025/1329
License: https://creativecommons.org/licenses/by-nc-sa/4.0/

BibTeX

@misc{cryptoeprint:2025/1329,
      author = {Alessio Caminata and Elisa Gorla and Madison Mabe and Martina Vigorito and Irene Villa},
      title = {Cryptanalysis of a multivariate CCZ scheme},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/1329},
      year = {2025},
      url = {https://eprint.iacr.org/2025/1329}
}