Table of contents

  • This session has been presented January 31, 2025 (13:45 - 14:45).

Description

  • Speaker

    Fangan Yssouf Dosso - Laboratoire SAS, École des Mines de Saint-Étienne

The Polynomial Modular Number System (PMNS) is an integer number system that aims to speed up arithmetic operations modulo a prime number p. This system is defined by a tuple (p, n, g, r, E), where p, n, g and r are positive integers, and E is a polynomial with integer coefficients, having g as a root modulo p
Arithmetic operations in PMNS rely heavily on Euclidean lattices. Modular reduction in this system is done using a lattice of zeros L (here, the set of polynomials in Z[X], with degrees smaller than n, having g as a root modulo p). 
Many works have shown that the PMNS can be an efficient alternative to the classical representation for modular arithmetic and cryptographic size integers.

In this presentation, we first present the PMNS and its arithmetic. Next, we introduce new properties of the lattice L, regarding a Montgomery-like coefficient reduction method. Then, we study the redundancy in the PMNS and explain how to choose the parameters for the desired redundancy in the system. Finally, we show how to use some properties of Euclidean lattices for efficient modular arithmetic and equality test within the PMNS. 


Reference: F. Y. Dosso, A. Berzati, N. El Mrabet, and J. Proy. PMNS revisited for consistent redundancy and equality test. Cryptology ePrint Archive, Paper 2023/1231, (\url{https://eprint.iacr.org/2023/1231})

Practical infos

Next sessions

  • Dissecting CRAFT, a full-round attack

    • September 18, 2026 (13:45 - 14:45)

    • Batiment 32A salle 15

    Speaker : Eran Lambooij - Inria

    I will present the first full-round key recovery attack on CRAFT, a block cipher introduced at ToSC 2019. The attack builds on the previous observation (ToSC 2026) that the state of CRAFT can be decomposed into two parts that barely exchange information. We transform this property into a dissection attack on the full-round cipher. This shows that in some cases we can elevate the dissection attack[…]
    • Cryptography

  • Key Attack on the ACDGV Matrix Encryption Scheme

    • September 25, 2026 (13:45 - 14:45)

    • IRMAR - Université de Rennes - Campus Beaulieu Bat. 22, RDC, Rennes - Amphi Lebesgue

    Speaker : Anmoal Porwal - Technical University of Munich

    I will present our key-recovery attack on the ACDGV public-key encryption scheme proposed at ASIACRYPT 2024 by Aragon, Couvreur, Dyseryn, Gaborit, and Vinçotte. The secret key is a Gabidulin code hidden by appending random rows and columns and by left- and right-multiplication with invertible matrices. Our attack exploits the resulting algebraic structure to recover an equivalent secret key. It[…]
    • Cryptography

    • Asymmetric primitive

  • Module Learning With Errors and Structured Extrapolated Dihedral Cosets

    • October 02, 2026 (13:45 - 14:45)

    • IRMAR - Université de Rennes - Campus Beaulieu Bat. 22, RDC, Rennes - Amphi Lebesgue

    Speaker : Jinwei Zheng - Télécom Paris

    The Module Learning With Errors (MLWE) problem is the fundamental hardness assumption underlying the key encapsulation and signature schemes ML-KEM and ML-DSA, which have been selected by NIST for post-quantum cryptography standardization. Understanding its quantum hardness is crucial for assessing the security of these standardized schemes.   Inspired by the equivalence between LWE and[…]
    • Cryptography

Show previous sessions