Explicit isogenies in quadratic time in any characteristic

Luca De Feo, Cyril Hugounenq, Jérôme Plût +1

Consider two elliptic curves $E,E^{\prime }$ defined over the finite field ${\mathbb{F}}_q$, and suppose that there exists an isogeny $\psi$ between $E$ and $E^{\prime }$. We propose an algorithm that de…