>From: "Geoffrey Faivre-Malloy" <[EMAIL PROTECTED]>
>Reply-To: <[EMAIL PROTECTED]>
>To: "Brian J. Beesley" <[EMAIL PROTECTED]>
>CC: <[EMAIL PROTECTED]>
>Subject: RE: Mersenne: The recent popularity of Factoring
>Date: Sun, 26 Mar 2000 09:34:49 -0500
>
> > Thanks for "coming clean".
>
>Hehehe...I was having fun while it lasted :)
>
> > I'd call it an "unwanted feature". George, I think perhaps the easy
> > way to handle this would be to check "UsePrimeNet" and refuse to
> > execute AdvancedFactor assignments if UsePrimeNet=1.
>
>I wouldn't say that it's an unwanted feature either. IMHO, I think
>Primenet
>should actually support it. If Primenet would support it and the client
>requested factors that hadn't been factored beyond a certain point, then
>none of this would have happened :) If primenet supported this feature and
>actually released the exponent and would give a new one(s) that weren't
>factored that high then it would be possible for those 486 machines that
>may
>be spending a long long time on one factor to specialize in factoring up
>to - say 54 bits or something.
I don't know enough about the network to judge your idea on its merits, but
I would say that 54 bits is somewhat low. A 486-33 would finish a 13 M
assignment to 54 bits within easily 2 or 3 minutes. 59 or 60 sounds like a
better idea.
>
>
> > A more general & more secure method of preventing the type of problem
> > exposed by this incident would be to have the server enforce a quota
> > for the maximum number of assignments issued to any user/computer id
> > combo in a particular time interval e.g. 20 per day. Yes, this could
> > still be got round by anyone determined to cause mischief by changing
> > the computer id and grabbing another bunch of assignments, but it
> > would be effective against accidents.
>
>A good idea although I don't know that I'd set the number this low. What
>if
>the person is going on vacation for an extended period of time? A quick
>machine can burn through factoring assignments like a knife through butter.
>
>G-Man
What about this: 300 assignments per month. Going on vacation? No problem.
Your machine grabs, say, 100 assignments out of its quote for the month
and it's set for three or four months.
Just so we know, how long would it take a 1.5 Ghz Athlon to factor 100
assignments through 64 bits? In view of Moore's Law, that's about what we
should figure on.
Regards,
Nathan Russell
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