526 résultats
-
Séminaire C2
11h30 Katharina Boudgoust (CR CNRS, LIRMM) : The Power of NAPs: Compressing OR-Proofs via Collision-Resistant HashingProofs of partial knowledge allow for proving the validity of t out of n different statements without revealing which ones those are. In this presentation, we describe a new approach for transforming certain proofs system into new ones that allows for proving partial knowledge. The[…] -
Post-quantum Group-based Cryptography
Orateur : Delaram Kahrobaei - The City University of New York
Group-based cryptography is a relatively new family in post-quantum cryptography, with high potential. I will give a general survey of the status of post-quantum group-based cryptography and present some recent results.In the second part of my talk, I speak about Post-quantum hash functions using special linear groups. This hash function is a generalization of Tillich-Zemor hash function as well[…] -
Polytopes in the Fiat-Shamir with Aborts Paradigm
Orateur : Hugo Beguinet - ENS Paris / Thales
The Fiat-Shamir with Aborts paradigm (FSwA) uses rejection sampling to remove a secret’s dependency on a given source distribution. Recent results revealed that unlike the uniform distribution in the hypercube, both the continuous Gaussian and the uniform distribution within the hypersphere minimise the rejection rate and the size of the proof of knowledge. However, in practice both these[…]-
Cryptography
-
Asymmetric primitive
-
Mode and protocol
-
-
Computational assumptions in the quantum world
Orateur : Alex Bredariol Grilo - LIP6 (CNRS / Sorbonne Université)
QKD is a landmark of how quantum resources allow us to implement cryptographicfunctionalities with a level of security that is not achievable only with classical resources.However, key agreement is not sufficient to implement all functionalities of interest, and it iswell-known that they cannot be implemented with perfect security, even if we have accessto quantum resources. Thus, computational[…]-
Cryptography
-
-
Solving the Tensor Isomorphism Problem for Special Orbits
Orateur : Valerie Gilchrist - ULB
Public key cryptography relies on using mathematical functions that are easy to compute but hard to invert. A recent work by D'Alconzo, Flamini, and Gangemi attempted to build such a function from tensors and use it to create a commitment scheme. In this talk, we will review their construction and present an attack on it, rendering it completely insecure. We will also offer an approach to[…]-
Cryptography
-
Asymmetric primitive
-
Protocols
-
-
Improved Provable Reduction of NTRU and Hypercubic Lattices
Orateur : Henry Bambury - ENS Paris
Lattice-based cryptography typically uses lattices with special properties to improve efficiency. We show how blockwise reduction can exploit lattices with special geometric properties, effectively reducing the required blocksize to solve the shortest vector problem to half of the lattice's rank, and in the case of the hypercubic lattice , further relaxing the approximation factor of blocks to . […]-
Cryptography
-
Asymmetric primitive
-