Skip to Content.
Sympa Menu

cado-nfs - Re: [Cado-nfs-discuss] DLP problem

Subject: Discussion related to cado-nfs

List archive

Re: [Cado-nfs-discuss] DLP problem


Chronological Thread 
  • From: Pierrick Gaudry <pierrick.gaudry@loria.fr>
  • To: ┃ Be Happy 、╯ <davidwu2538@qq.com>
  • Cc: cado-nfs-discuss-owner <cado-nfs-discuss-owner@lists.gforge.inria.fr>
  • Subject: Re: [Cado-nfs-discuss] DLP problem
  • Date: Sat, 1 Dec 2018 14:43:20 +0100
  • List-archive: <http://lists.gforge.inria.fr/pipermail/cado-nfs-discuss/>
  • List-id: A discussion list for Cado-NFS <cado-nfs-discuss.lists.gforge.inria.fr>
  • Resent-date: Sat, 1 Dec 2018 15:01:32 +0100
  • Resent-from: Pierrick Gaudry <gaudry@bratwurst.loria.fr>
  • Resent-message-id: <20181201140132.GC30217@bratwurst.loria.fr>
  • Resent-to: cado-nfs-discuss <cado-nfs-discuss@lists.gforge.inria.fr>

Dear David,

Could you have a look at the following thread on this mailing-list :

https://lists.gforge.inria.fr/pipermail/cado-nfs-discuss/2018-November/000939.html

It seems that this answers your question.

Best regards,
Pierrick

On Sat, Dec 01, 2018 at 08:12:36AM +0800, ┃ Be Happy 、╯ wrote:
> I am not sure if I did this right, but I met a problem and I can't solve it.
>
> I use the example you give in README.dlp:
> $ ./cado-nfs.py -dlp -ell 101538509534246169632617439
> target=92800609832959449330691138186 191907783019725260605646959711
> and the answer is:
> p = 191907783019725260605646959711
> ell = 101538509534246169632617439
> log2 = 35338258800684599318721749
> log3 = 62614277196775799921779143
> The other logarithms of the factor base elements are in
> /tmp/cado.yliqctwz/p30.dlog
> target = 92800609832959449330691138186
> log(target) = 32359472153599817010011705
>
> For the discrete logarithm of primitive root 2 (i.e. g=2), only log
> (target)/log2 mod ell, and the answer is
> 5995158352878681776097204.
>
> But when I want to check out if the answer is right, so I compute
> 2^5995158352878681776097204 (mod 191907783019725260605646959711)
> I get 36195192389531979502867378706 and it's obviously not target.
>
>
> I and my classmate have the same problem and I don't know what is wrong.
>
>
> and I don't know how to build a file if I want to compute a 78-digit p,
> could you please help me?
>
>
> Cheers!
>
>
> David Wu




Archive powered by MHonArc 2.6.19+.

Top of Page