Description
The NTRU problem is an algorithmic problem over structured lattices that was introduced by Hoffstein, Pipher, and Silverman more than 20 years ago, and which has been used to construct various cryptographic primitives. However, its relation to other lattice problems is still not well understood.<br/> In this talk, we will describe different variants of the NTRU problem, and study how they compare to each other (and to other more classical lattice problems) in terms of reductions. More precisely, we will show that a search variant of the NTRU problem is at least as hard as the shortest vector problem (SVP) in ideal lattices; and that the decisional variant of NTRU is at least as hard as another search variant of NTRU. Unfortunately, the two search variants of NTRU that are considered in these reductions do not match, meaning that we cannot combine the reductions in order to obtain a reduction from the ideal shortest vector problem to the decisional NTRU problem. This is a joint work with Damien Stehlé.<br/> lien: https://univ-rennes1-fr.zoom.us/j/97066341266?pwd=RUthOFV5cm1uT0ZCQVh6QUcrb1drQT09
Prochains exposés
-
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[…]-
Cryptographie
-
-
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[…]-
Cryptographie
-
Primitive asymétrique
-
Mode et protocole
-
-
Post-quantum Group-based Cryptography
Orateur : Delaram Kahrobaei - The City University of New York