Table of contents

  • This session has been presented April 12, 2019.

Description

  • Speaker

    Alain Passelègue - Inria

In this talk, I will present new and simple candidate PRFs introduced in a recent work. In this work, we depart from the traditional approaches for building PRFs used in provable security or in applied cryptography by exploring a new space of plausible PRF candidates. Our guiding principle is to maximize simplicity while optimizing complexity measures that are relevant to advanced cryptographic applications. Our primary focus is on weak PRFs computable by very simple circuits (depth-2 ACC circuits).<br/> The advantage of our approach is twofold. On the theoretical side, the simplicity of our candidates enables us to draw many natural connections between their hardness and questions in complexity theory or learning theory. On the applied side, the piecewise-linear structure of our candidates lends itself nicely to applications in secure multiparty computation (MPC). In particular, we construct protocols for distributed PRF evaluation that achieve better round complexity and/or communication complexity compared to protocols obtained by combining standard MPC protocols with practical PRFs (included MPC-friendly ones). Finally, we introduce a new primitive we call an encoded-input PRF, which can be viewed as an interpolation between weak PRFs and standard (strong) PRFs. As we demonstrate, an encoded-input PRF can often be used as a drop-in replacement for a strong PRF, combining the efficiency benefits of weak PRFs and the security benefits of strong PRFs. We give a candidate EI-PRF based on our main weak PRF candidate.<br/> Joint work with Dan Boneh, Yuval Ishai, Amit Sahai, and David J. Wu, published at TCC 2018<br/> lien: http://desktop.visio.renater.fr/scopia?ID=728898***2055&autojoin

Next sessions

  • Lie algebras and the security of cryptosystems based on classical varieties in disguise

    • November 07, 2025 (13:45 - 14:45)

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

    Speaker : Mingjie Chen - KU Leuven

    In 2006, de Graaf et al. proposed a strategy based on Lie algebras for finding a linear transformation in the projective linear group that connects two linearly equivalent projective varieties defined over the rational numbers. Their method succeeds for several families of “classical” varieties, such as Veronese varieties, which are known to have large automorphism groups.   In this talk, we[…]

    • Cryptography

  • Some applications of linear programming to Dilithium

    • November 14, 2025 (13:45 - 14:45)

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

    Speaker : Paco AZEVEDO OLIVEIRA - Thales & UVSQ

    Dilithium is a signature algorithm, considered post-quantum, and recently standardized under the name ML-DSA by NIST. Due to its security and performance, it is recommended in most use cases.   During this presentation, I will outline the main ideas behind two studies, conducted in collaboration with Andersson Calle-Vierra, Benoît Cogliati, and Louis Goubin, which provide a better understanding of[…]

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

    • November 21, 2025 (13:45 - 14:45)

    • Salle Guernesey à l'ISTIC

    Speaker : 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

    • November 28, 2025 (13:45 - 14:45)

    • Batiment 32B salle 12

    Speaker : 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

    • December 05, 2025 (13:45 - 14:45)

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

    Speaker : 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

Show previous sessions
Page top