592 results

  • On some efficiency aspects of the CKKS fully homomorphic encryption scheme

    • May 17, 2024

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

    Speaker : Damien Stehlé - Cryptolab

    Fully homomorphic encryption (FHE) is a form of encryption that allows arbitrary computations on data without requiring to decrypt the ciphertexts. Among the diverse FHE schemes, CKKS is designed to efficiently perform computations on real numbers in an encrypted state. Interestingly, Drucker et al [J. Cryptol.] recently proposed an efficient strategy to use CKKS in a black-box manner to perform[…]
  • Correction of dual lattice attacks

    • April 19, 2024

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

    Speaker : 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

    • April 12, 2024

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

    Speaker : 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)

    • April 05, 2024

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

    Speaker : 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

    • March 29, 2024

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

    Speaker : 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

    • March 22, 2024

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

    Speaker : 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[…]