Re: New experimental GP interface for elliptic curves over finite fields

[Bill Allombert <Bill.Allombert@math.u-bordeaux1.fr>]

On Mon, Sep 03, 2012 at 11:42:22PM +0200, Bill Allombert wrote:
> On Thu, Jul 26, 2012 at 08:33:37PM +0200, Bill Allombert wrote:
> > On Thu, Jul 12, 2012 at 07:47:37PM +0200, Bill Allombert wrote:
> > I have added support for supersingular curves over finite field of characteristic 2,
> > and corrected a lot of bugs.
> 
> I have reimplemented the support for ordinary curves over finite field of characteristic 2
> to use Harley algorithm. This is much faster now.
> 
> ? a=ffgen(ffinit(2,1024),'a);ellffinit([1,0,0,0,a],a,1);
> ? ##
>   ***   last result computed in 11,482 ms.

Now, I have added support for curves over finite field of characteristic 3 and
I have implemented Harley algorithm for char 3.

? a=ffgen(ffinit(3,646),'a); E=ellffinit([0,1,0,0,a],a,1);
? ##
  ***   last result computed in 7,780 ms.

I will probably implement a variant of Harley algorithm for char 5.

I like to thanks Damien Robert for his help with the formulas.

Cheers,
Bill.