We show that the soundness proof for the De Feo–Jao–Plût identification scheme (the basis
for supersingular isogeny Diffie–Hellman (SIDH) signatures) contains an invalid assumption …

Modern key exchange protocols are usually based on the Diffie–Hellman (DH) primitive. The
beauty of this primitive, among other things, is its potential reusage of key shares: DH shares …

In 2016, Galbraith et al. presented an adaptive attack on the SIDH key exchange protocol. In
SIKE, one applies a variant of the Fujisaki-Okamoto transform to force Bob to reveal his …

Isogeny‐based cryptography is a promising approach for post‐quantum cryptography. The
best‐known protocol following that approach is the supersingular isogeny Diffie–Hellman …

We present a polynomial-time adaptive attack on the genus-2 variant of SIDH (G2SIDH) and
describe an improvement to its secret selection procedure. G2SIDH is a generalisation of the …

In spite of the wave of devastating attacks on SIDH, started by Castryck-Decru (Eurocrypt
2023), there is still interest in constructing quantum secure SIDH Proofs of Knowledge …

This thesis presents multiple results concerning the cryptanalysis and design of
isogenybased primitives and advanced protocols which aim to provide security in the …

The advent of quantum computers renders most cryptographic protocols obsolete and urges
for a quick transition to post-quantum solutions. Many valid techniques for quantum-secure …

Isogeny-based cryptography is one of the contenders for providing cryptosystems based on
mathematical problems which are assumed to be hard for both classical and quantum …

Let $ E $ be a supersingular elliptic curve over a finite field. In this document we study public-
key encryption schemes which use non-constant rational maps from $ E $. The purpose of …