From: Andy Wingo <wingo@pobox.com>
To: Mark H Weaver <mhw@netris.org>
Cc: guile-devel@gnu.org
Subject: Re: Improve `seed->random-state' in stable-2.0?
Date: Fri, 20 Jan 2012 15:54:27 +0100 [thread overview]
Message-ID: <87ipk6tof0.fsf@pobox.com> (raw)
In-Reply-To: <87d3afvyr6.fsf@netris.org> (Mark H. Weaver's message of "Thu, 19 Jan 2012 22:28:13 -0500")
On Fri 20 Jan 2012 04:28, Mark H Weaver <mhw@netris.org> writes:
> `seed->random-state' is poorly implemented when passed a numeric
> argument. It converts the number to a decimal string, and then
> `scm_i_init_rstate' takes over and basically adds every 8th byte
> together to form the 64-bit internal state.
Is that what it does?
I agree that it's a pretty bad initializer to a pretty bad PRNG, but
from what I can tell, it does use all of the bytes in the input. They
aren't very dense bytes, entropy-wise, but there are more of them, so I
think the amount of entropy added to the seed is the same.
Dunno. Am I reading that code wrong?
Regards,
Andy
--
http://wingolog.org/
next prev parent reply other threads:[~2012-01-20 14:54 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-20 3:28 Improve `seed->random-state' in stable-2.0? Mark H Weaver
2012-01-20 8:37 ` David Kastrup
2012-01-20 14:54 ` Andy Wingo [this message]
2012-01-20 18:52 ` Mark H Weaver
2012-01-20 20:35 ` Andy Wingo
2012-01-20 22:45 ` Mark H Weaver
2012-01-21 7:38 ` David Kastrup
2012-01-21 8:20 ` Mark H Weaver
2012-01-23 9:52 ` Andy Wingo
2012-01-20 23:46 ` Mike Gran
2012-01-23 9:55 ` Andy Wingo
2012-01-23 13:06 ` Mike Gran
2012-01-23 14:06 ` Andy Wingo
2012-01-24 6:08 ` Mike Gran
2012-01-24 9:56 ` Andy Wingo
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