Re: real random

In
<b048de57-aaad-4cb4-b144-a61a4e573183@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
websnarf wrote:

On Sep 20, 12:16 pm, Richard Heathfield <r...@xxxxxxxxxxxxxxx>
wrote:
In
<7cc69756-f72f-4d40-a895-41253a923...@xxxxxxxxxxxxxxxxxxxxxxxxxxx>,
websnarf wrote:
On Sep 20, 1:23 pm, "Bill Cunningham" <nos...@xxxxxxxxxxxxx>
wrote:
Can anyone show me a skeleton code for *real* random numbers?
Not just using srand and rand that sometimes depends on the
clock.

Asking people in comp.lang.c for "real random numbers" is like
asking a chiropractor for the recipe for coca cola. There simply
is no expertise whatsoever in the typical people in this news
group on that question.

You seem determined to prove that claim by example.

How many people said the word "Fortuna" in their responses to Bill?

How many non sequiturs can we manage?

Quoting you was just a useful way to give an example of a totally
useless and wrong answer.

I stand by my answer.

But it appears I could literally have
quoted *anyone* else in this thread. That's just your penalty for
being first.

I stand by my answer.

Not surprisingly you get nonsense like: "No algorithm can produce
a truly random number sequence" which is tantamount to religious
evangelism.

Feel free to post such an algorithm, then.

I described one ...

Algorithms have several characteristics:

1) finiteness;
2) definiteness;
3) input;
4) output;
5) effectiveness.

If you regard Fortuna as being a single transition from one number to
another, it hardly qualifies as a sequence generator. If you regard
it as a generator of a stream of numbers, it is not finite.
Therefore, it is not an algorithm. Furthermore, it fails to meet the
fifth criterion, that of effectiveness (in Knuth's sense - i.e. that
it is sufficiently basic that the results can in principle be done
exactly by a human being with paper and pencil such that they get
exactly the same result as the computer, which can't be the case for
any process that involves gathering arbitrary data at runtime).

Less pickily: what I actually said was: "No algorithm can produce a
truly random number sequence. You need a genuine source of entropy,
such as a plasma lamp, a video camera pointing at (say) busy traffic,
a radioactive source, or perhaps weather data. Better still, two or
more such sources, mixed together."

By suggesting Fortuna (which gathers genuine entropy as it goes), you
are agreeing with me.

do you not read or something?

If you have to be wrong, be polite. If you can't be polite, be right.
(Better still, be both, but we're all human.) Your predilection for
being impolite /and/ wrong is not good for you.

<snip>

Anyways, the problem of generating random numbers is just an
exercise in understanding.

Numbers aren't random. Number generation processes can be random.

?

Are you claiming that numbers /are/ random? Is 6 random? How about 42?
How do you feel about 117? And what about 3.14159265368979323846?

So first you have to start with the definition of "random". It
just means the opposite of deterministic.

You can mean that if you like, but it's a very humpty-dumpty way of
looking at randomness.

No. I am defining it *correctly*.

How you define it is up to you, and irrelevant to this discussion. The
acid test of practical randomness is not determinism, but
predictability.

You just don't realize the you are *NOT*; and that that is your
primary problem.

Look up "irony" when you get a minute.

If you can't generate random numbers then no online poker
website could possibly be in operation without being
hacked to death.

Numbers are not of themselves either random or non-random. It is
processes for generating numbers that are either random or
non-random. Furthermore, you appear to have misread my article
completely. I didn't say you can't have a true RNG. I said you can't
have a true RNG *algorithm*. I pointed out, rather clearly I thought,
that you need a genuine source of entropy if you're going to have a
truly random process. And in blunders Mr Hsieh, saying "Ha! You're
wrong to claim X! The truth is actually X!"

In short, learn to read.

[Poker sites are viable.] How could that be possible if you can't
generate random numbers?

I can generate random numbers just fine, thanks - by using a genuine
source of entropy.

You think black hat hackers are less
incentivised by money than they are by mere copyright infringement?

No, but I do think they can read better than you.

<snip>

The letter of what he's asking for is an entropy source, not a PRNG.

Yes. Well done. If you just think a little harder, you'll realise what
a prize donkey you've made out of yourself.

<snip>

--
Richard Heathfield <http://www.cpax.org.uk>
Email: -http://www. +rjh@
"Usenet is a strange place" - dmr 29 July 1999
Sig line vacant - apply within
.

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