Faster computation of isogenies of large prime degree

Daniel Bernstein, Luca de Feo, Antonin Leroux +1

Let $\mathcal{E}/{\mathbb{F}}_q$ be an elliptic curve, and $P$ a point in $\mathcal{E}({\mathbb{F}}_q)$ of prime order $\ell$. Vélu's formulae let us compute a quotient curve $\mathcal…