20150610, 21:34  #1 
Aug 2002
Rovereto (Italy)
10011111_{2} Posts 
This is weird... Isn't it?
Is this the same result or not?...

20150610, 22:56  #2 
May 2013
East. Always East.
11×157 Posts 
The ECM method isn't deterministic. You don't get a yesorno answer from running a single curve. Part of what defines each curve is randomized so no two are likely to be the same. You get increased probabilities of finding a factor (if one is there) by running more. The user probably requested / submitted their curves in batches of 100 which is a bit odd since I think you have seriously diminishing returns at that curve count.

20150610, 23:03  #3 
Aug 2002
Rovereto (Italy)
159_{10} Posts 
I know that. My question was about how Primenet may distinguish from two (or more) different results if all the parameters (number of curves, boundaries, ...) it gets are the same... Or it knows that each curve is unic so that each result is unic as well...

20150611, 00:34  #4  
"Curtis"
Feb 2005
Riverside, CA
2^{3}×7^{2}×11 Posts 
Quote:
Primenet has no way to know the user isn't submitting fraudulent curve counts. Luckily, the nature of ECM is that a future user running curves of the same or larger size will usually find any factor the fraudulent user "would have" found. 

20150611, 03:27  #5  
Serpentine Vermin Jar
Jul 2014
110011001010_{2} Posts 
Quote:
Since each curve has it's own random starting point, I wonder if a good way to avoid duplicate submissions would be to have Prime95 do a hash of the different ones for each curve and include that in the result. Then the Prime95 checksum would take that into account, which should result in unique results for each set of curves? I'm probably not saying anything nobody else has ever thought of, so I'll retreat back into my corner now. 

20150611, 04:40  #6 
Basketry That Evening!
"Bunslow the Bold"
Jun 2011
40<A<43 89<O<88
16065_{8} Posts 
No, PrimeNet unfortunately does not record the sigma for any given curve. (sigma is the standard variable in the literature that uniquely defines each curve.)

20150611, 04:50  #7 
Undefined
"The unspeakable one"
Jun 2006
My evil lair
3×23×83 Posts 
And it is not just ECM that "suffers" from this problem. TF with a negative result is a trustonly thing also. We can't possibly know if any curves/TF were ever run.when the user reports no factors without doing all the work again on another system.
Fortunately the credits earned for nofactor results have no real world meaning so it really doesn't matter too much, the incentive the cheat is very low. More likely it is just a misconfiguration or misunderstanding. Except for perhaps a few extra LL/DC tests that could have been avoided no real harm is caused. 
20150611, 11:38  #8 
Banned
"Luigi"
Aug 2002
Team Italia
2×2,383 Posts 
No, it's not. It was a bunch of 100 curves done on different PCs and submitted all together. The sigma values should be all different.
Unfortuntely, at the moment there is no way for Primenet to tell it from a forged result. Luigi 
20150611, 12:04  #9  
Aug 2002
Rovereto (Italy)
3×53 Posts 
Quote:
I was just wondering... I'm starting right now to look at ECM factoring... Never done that job before... Regards 

20150611, 12:10  #10  
Aug 2002
Rovereto (Italy)
9F_{16} Posts 
Quote:


20150611, 12:12  #11 
Aug 2002
Rovereto (Italy)
3·53 Posts 

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