Sommaire

  • Cet exposé a été présenté le 31 janvier 2025 (13:45 - 14:45).

Description

  • Orateur

    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})

Infos pratiques

Prochains exposés

  • Wagner’s Algorithm Provably Runs in Subexponential Time for SIS^∞

    • 21 novembre 2025 (13:45 - 14:45)

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

    Orateur : Johanna Loyer - Inria Saclay

    At CRYPTO 2015, Kirchner and Fouque claimed that a carefully tuned variant of the Blum-Kalai-Wasserman (BKW) algorithm (JACM 2003) should solve the Learning with Errors problem (LWE) in slightly subexponential time for modulus q = poly(n) and narrow error distribution, when given enough LWE samples. Taking a modular view, one may regard BKW as a combination of Wagner’s algorithm (CRYPTO 2002), run[…]
    • Cryptography

  • CryptoVerif: a computationally-sound security protocol verifier

    • 28 novembre 2025 (13:45 - 14:45)

    • Batiment 32B salle 12

    Orateur : Bruno Blanchet - Inria

    CryptoVerif is a security protocol verifier sound in the computational model of cryptography. It produces proofs by sequences of games, like those done manually by cryptographers. It has an automatic proof strategy and can also be guided by the user. It provides a generic method for specifying security assumptions on many cryptographic primitives, and can prove secrecy, authentication, and[…]
    • Cryptography

  • Structured-Seed Local Pseudorandom Generators and their Applications

    • 05 décembre 2025 (13:45 - 14:45)

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

    Orateur : Nikolas Melissaris - IRIF

    We introduce structured‑seed local pseudorandom generators (SSL-PRGs), pseudorandom generators whose seed is drawn from an efficiently sampleable, structured distribution rather than uniformly. This seemingly modest relaxation turns out to capture many known applications of local PRGs, yet it can be realized from a broader family of hardness assumptions. Our main technical contribution is a[…]
    • Cryptography

  • Predicting Module-Lattice Reduction

    • 19 décembre 2025 (13:45 - 14:45)

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

    Orateur : Paola de Perthuis - CWI

    Is module-lattice reduction better than unstructured lattice reduction? This question was highlighted as `Q8' in the Kyber NIST standardization submission (Avanzi et al., 2021), as potentially affecting the concrete security of Kyber and other module-lattice-based schemes. Foundational works on module-lattice reduction (Lee, Pellet-Mary, Stehlé, and Wallet, ASIACRYPT 2019; Mukherjee and Stephens[…]
    • Cryptography

Voir les exposés passés