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Old 2018-05-25, 06:18   #2
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Sep 2003

22·3·5·43 Posts

Originally Posted by Lexicographer View Post
Issue #1: I've asked PrimeNet for a trial factoring assignment for M1277 on the Manual Testing page and it gave me ECM assignment,
There is no point doing any further trial factoring of this exponent. Indeed, there was no point taking it to 65 bits as someone did last year. That was a wasted effort.

Trial factoring can only search for relatively small factors because the difficulty goes up by a factor of two each time you increment the bit size, so once you hit a certain point you have to try other methods, like P−1 or ECM. And enough ECM has been done on this exponent by now to demonstrate that the smallest factor must be many, many, many, many times too large to be be found by trial-factoring. Here "must" is probabilistic rather than absolutely proven, but the odds are beyond astronomical.

Originally Posted by Lexicographer View Post
Isn't it a massive waste of processing power to give the same assignment to multiple users again and again?
I thought, the point of PrimeNet is to coordinate people's effort, not to make them run same task over and over.
It's not the same task. Each ECM curve has a different (random) sigma. It's like throwing multiple darts at a dartboard, hoping that one will eventually hit a bullseye.

By contrast, redoing P−1 testing with the same B1 and B2 parameters really would be duplicating the same work over again.

Last fiddled with by GP2 on 2018-05-25 at 06:47
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