@article{BoMoSaSc08,
    author      = {Bostan, Alin and Morain, Fran\c{c}ois and Salvy, Bruno and
  Schost, {\'E}ric},
    title       = {Fast algorithms for computing isogenies between elliptic
  curves},
    journal     = {Mathematics of Computation},
    number      = {263},
    year        = {2008},
    month       = {July},
    volume      = {77},
    pages       = {1755--1778},
    doi         = {10.1090/S0025-5718-08-02066-8},
    arxiv       = {abs/cs/0609020},
    abstract    = {We survey algorithms for computing isogenies between
  elliptic curves defined over a field of characteristic either 0 or a large
  prime. We introduce a new algorithm that computes an isogeny of degree $\ell$
  ($\ell$ different from the characteristic) in time quasi-linear with respect
  to $\ell$. This is based in particular on fast algorithms for power series
  expansion of the Weierstrass $\wp$-function and related functions.},
}