Motivated by the recent applications of isogeny graphs in cryptography, we review topics related to isogenies of elliptic curves defined over finite fields, and their computations. Isogeny graphs come in two families: complex multiplication (CM) and supersingular. CM graphs enjoy

In 2011, Gregor Leander et al. found a new type of attacks against lightweight block ciphers called Invariant attacks. Four years later, this class of attacks has been generalized by Todo and Leander into the nonlinear invariant attacks. It appeared

MDS matrices are essential in symmetric-key cryptography since they provide optimal diffusion in block ciphers. Many MDS matrices are known, but a problem remains which gathers a lot of attention: finding lightweight MDS matrices. Several approaches exist, namely reducing the

The HiMQ-3 signature scheme is a very efficient multivariate signature scheme and was one of the first round candidates of the NIST post-quantum standardization process. In this talk we present a new attack against HiMQ-3, the so called singularity attack.

The generalized birthday problem, or k-xor problem, has many applications in cryptography. Interestingly, there is a gap between its provable query complexity and its best known time complexity, obtained with Wagner’s algorithm. Quantum algorithms for this problem have been studied

For enabling post-quantum cryptanalytic experiments on a meaningful scale, there is a strong need for low-memory algorithms. We show that the combination of techniques from representations, multiple collision finding, and the Schroeppel-Shamir Algorithm leads to improved low-memory algorithms. For random

La cryptographie incrémentale permet d’obtenir des applications plus performantes et plus économes en ressources énergétiques (serveurs, appareils sur batterie). Elle se place dans le vaste contexte où des documents dont nous disposons des formes cryptographiques (p. ex. des chiffrés, des

Secure Multi-Party Computation (MPC) allows a set of "n" distrusting parties to compute functions on their private inputs while guaranteeing secrecy of inputs while ensuring correctness of the computation. Most MPC protocols can achieve such security only against a minority

Linear cryptanalysis is an extremely important consideration when evaluating the security of symmetric primitives. After its introduction by Matsui in 1993, it has been largely extended and improved, and it has led to attacks on multiple ciphers. One of these