624 résultats

  • Correction of dual lattice attacks

    • 19 avril 2024

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

    Orateur : Kevin Carrier - CY Cergy

    The security of cryptographic systems such as Kyber and Dilithium (currently undergoing standardization by NIST) fundamentally hinges on the Learning With Errors (LWE) problem. However, the state of the art for attacking this problem is not yet entirely clear. Specifically, the validity of dual attacks on LWE is currently under scrutiny due to their analyses relying on heuristics that have proven[…]
  • Generic SCARE: reverse engineering without knowing the algorithm nor the machine

    • 12 avril 2024

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

    Orateur : Hélène LE BOUDER - IMT Atlantique

    A novel side-channel-based reverse engineering technique is introduced, capable of reconstructing a procedure solely from inputs, outputs, and traces of execution. Beyond generic restrictions, no prior knowledge of the procedure or the chip it operates on is assumed. These restrictions confine the analysis to 8-bit RISC constant-time software implementations. Specifically, the feasibility of[…]
  • TBD (To be decided closer to the date of the talk)

    • 05 avril 2024

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

    Orateur : Lisa Kohl - CWI

    TBD (To be decided closer to the date of the talk)
  • Ind-cpa-d insecurity of approximate and exact homomorphic encryption schemes

    • 29 mars 2024

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

    Orateur : Elias Suvanto - Cryptolab

    Fully Homomorphic Encryption enables the evaluation of arbitrary circuits over encrypted data while maintaining the confidentiality of the underlying messages. It greatly enhances functionality but also comes with security challenges for some applications like Threshold FHE. While the standard IND-CPA security is sufficient against honest but curious adversaries, a stronger security notion called[…]
  • Recent advances in post-quantum signatures based on the MPC-in-the-Head paradigm

    • 22 mars 2024

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

    Orateur : Thibauld Feneuil - CryptoExperts

    Zero-knowledge proofs of knowledge are useful tools for designing signature schemes. Among the existing techniques, the MPC-in-Head (MPCitH) paradigm provides a generic framework to build quantum-resilient proofs using techniques from secure multiparty computation. This paradigm has recently been improved in a series of works which makes it an effective and versatile tool. In this talk, I will[…]
  • Updatable Public Key Encryption with Lattices

    • 23 février 2024

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

    Orateur : Calvin Abou-Haidar - ENS Lyon

    Updatable public key encryption has recently been introduced as a so- lution to achieve forward-security in the context of secure group messaging without hurting efficiency, but so far, no efficient lattice-based instantia- tion of this primitive is known. In this work, we construct the first LWE-based UPKE scheme with polynomial modulus-to-noise rate, which is CPA-secure in the standard model. At[…]