Come on... this is getting slightly ridiculous. It's a proven fact that you
can't write an algorithm that determines if _any_ given program terminates.
Giving me two concrete programs doesn't prove anything. Your P2 has to give
the correct answer for every possible P1.
There's no "myth" to be dispelled; it's a theorem that's been proven
mathematically.
-Stefan
----- Original Message -----
From: "JF" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Friday, May 11, 2001 9:05 PM
Subject: Re: [freenet-tech] Ideas for a FreeNet Process
> No prob.
> Dispelling myths is part of hacking.
> I gave Steven 2 programs.
> one that would run in an infinite loop and one that would determine if the
> first on would run in an infinite loop.
>
> Its the examination of these rules that will make things secure do
> tongue-in-cheek at will.
>
> HackerKungFu
>
> ----- Original Message -----
> From: "Guy Smith" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Friday, May 11, 2001 2:56 PM
> Subject: RE: [freenet-tech] Ideas for a FreeNet Process
>
>
> > Actually, the halting problem is undecidable in the *general* case.
There
> > are plenty of special cases in which it can be decided. If you limit
> > yourself to only accepting code that falls within these special cases,
> > you're fine. Sure, you restrict yourself to only a subset of all
possible
> > software, but you gain a rigorous proof that the software will halt (or
> > not).
> >
> > Not that this really applies to what was a tongue-in-cheek comment.
> >
> > --Guy
> >
> > -----Original Message-----
> > From: Stefan Reich [mailto:[EMAIL PROTECTED]]
> > Sent: Friday, May 11, 2001 2:34 PM
> > To: [EMAIL PROTECTED]
> > Subject: Re: [freenet-tech] Ideas for a FreeNet Process
> >
> >
> > > > Not a problem; just write a function that can scan any arbitrary
piece
> > of
> > > > code and determine whether it will eventually halt or not.
> > >
> > > Right in other words, the freenet could determine cancer nodes and
deal
> > with
> > > them.
> >
> > Ahm... I think you missed out on the irony in that statement... it is
> > IMPOSSIBLE to write an algorithm that decides if a given piece of code
> will
> > halt eventually (i think Turing proved that).
> >
> > I think you still don't understand the problem with the execution of
> > untrusted code (is it so unobvious?).
> >
> > -Stefan
> >
> >
> > _______________________________________________
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> > http://lists.freenetproject.org/mailman/listinfo/tech
> >
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> >
>
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