2005-08-08, 16:36 | #1 |
Apr 2003
2^{2}·193 Posts |
Any interest in some low n ECM factoring?
Hi,
i am doing some ECM factoring on low n. Anyone interested to help me out a little bit? And yes i know it will not bring the project ahead i am doing it just for fun. Lars |
2005-08-08, 17:36 | #2 |
May 2005
Copenhagen, Denmark
17^{2} Posts |
Care to explain a not-mathematician what it's about and how you do it?
I've got my Pentium M 1.6 GHz laptop (not running 24/7) which (when I'm finished with S/R B5) I might consider using for other stuff, maybe this. Last fiddled with by OmbooHankvald on 2005-08-08 at 17:38 |
2005-08-08, 18:20 | #3 |
Jun 2003
3·5·107 Posts |
Could you post a list of k and n you want to factor. I could run some curves. (what bounds you want us to run will be helpful)
Citrix Ps: I am going to use http://www.alpertron.com.ar/ECM.HTM |
2005-08-08, 18:34 | #4 |
Apr 2003
2^{2}×193 Posts |
I will try my best to describe it and hope that somebody else corrects all my errors.
There are several methods to find a factor for a given number. For example we use sieving to find factors for as many numbers as possible before we do a PRP test to check if a number is prime or not. At the moment we find factors that are 13 Digits long with sieving. There are other methods called "p-1","p+1" and ECM. These methods can find factors that are much longer but it takes also alot of time time compared to do a PRP test. Don't ask me about the math behind it. I just know how to set up a test. For the fun of finding some large factors (30 digits and larger at the moment) i started to run p-1 and ECM on all non factored k/n pairs with n less then 2000. There are 26 n left where i found no factor less then 25 digits. (For the experts B1=50000) For 13 of them i also finished the 30 digit level (B1=250000) and for the other 13 i should have finished that level in 2 days. To help you can use either Prime95 or ECM6. I am using ECM6. Lars |
2005-08-08, 18:38 | #5 |
Jun 2003
645_{16} Posts |
Where do you get the binaries for ECM6? You only want to find the lowest factor or factorize the whole number?
Citrix |
2005-08-08, 18:45 | #6 |
Apr 2003
2^{2}·193 Posts |
Here is a list of the values that need ECM at B1=1000000.
To complete this B1 level each of the numbers needs 950 curves. 237019*2^1006+1 : 1*10^6 | 60 : done 152267*2^1059+1 : 1*10^6 | 61 : done 168451*2^1116+1 : 1*10^6 | 60 : done 265711*2^1128+1 : 1*10^6 | 60 : done 149183*2^1157+1 : 1*10^6 | 60 : done 258317*2^1167+1 79817*2^1191+1 214519*2^1194+1 222113*2^1221+1 149183*2^1309+1 258317*2^1311+1 237019*2^1330+1 265711*2^1344+1 : 1*10^6 | 1 : done The other 13 ( hopefully less) will follow when i have finished B1=250000. 237019*2^1006+1 is my most wanted as it is the lowest unfactored n. @Citrix: As far as i know the the ECM you want to use is slow compared to ECM6. I have precompiled windows version for P3,P4,Athlon and Athlon64. ( No i did not make the compilation but found the links somewhere here in one of the forums) Lars Last fiddled with by ltd on 2005-08-09 at 15:53 |
2005-08-08, 18:49 | #7 |
Jun 2003
3·5·107 Posts |
Could you provide me a link to the binary for p4! (or upload it or email it to me). I will try to look in the other forms.
I will start with 152267*2^1059+1 Citrix |
2005-08-08, 18:53 | #8 |
Apr 2003
2^{2}·193 Posts |
I found the binaries under the following link:
http://www.pa.uky.edu/~childers/ecm6.zip If you want to read the thread where if found the link: http://www.mersenneforum.org/showthr...6&page=3&pp=50 I only want to find one factor and not the complete factorisation so you should use the "-one" option. Lars |
2005-08-08, 19:26 | #10 |
Jun 2003
3·5·107 Posts |
I will return my k, I can't get the exe to work. Though I did 1 curve using the applet.
Citrix |
2005-08-08, 19:27 | #11 |
Jun 2003
3·5·107 Posts |
Ill try p-1. What bounds have you used for p-1, though it seems unlikely that I will find a factor.
Citrix |
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