From: Rick Busdiecker <rfb@lehman.com>
Date: Mon, 25 Sep 95 10:10:42 PDT
To: m5@dev.tivoli.com (Mike McNally)
Subject: Re: `Random' seed.
In-Reply-To: <9509251229.AA23816@alpha>
Message-ID: <9509251300.AA22090@cfdevx1.lehman.com>
MIME-Version: 1.0
Content-Type: text/plain


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    From: m5@dev.tivoli.com (Mike McNally)
    Date: Mon, 25 Sep 1995 07:29:01 -0500
    
    I also have some doubts as to the randomness of this; I suspect
    that the kernel is rather deterministic in its scheduling
    practices.

I don't think that anyone has suggested otherwise.  I believe that
`clock skew' was the underlying source of randomness that Matt Blaze
mentioned in the message where I first saw that code.

In any case, a number of people have expressed interest in seeing
signs of non-random behavior.  As far as I know, no one has said
anything if they've found such signs.  I've tried to find some, but
only with very simple tests.  I generated a quarter megabits and found
that:

 - I can only compress it to about 32Kb, i. e. 256 k bits.  Tim May
   has suggested that compressibility is getting to be a good metric
   for entropy.

 - It seems to contain roughly equal numbers of:
    * 0s and 1s
    * 00s, 01s, 10s, and 11s
    * etc. I forget how high I checked.

 - It contains some rather long sequences of 0s and 1s.  I think on
   the order of 20.

I have no idea how reasonable it would be to use this approach in
Netscape, however if it were available as an option to generate, say
300 bits, I'd personally be plenty willing to let it chew up five
minutes while I get my morning caffeine.  I realize that some people
would not.  It certainly couldn't hurt to throw a few bits gathered
this way into the mix.  Also, it may be possible to get more than one
bit of entropy per second using this approach, I was merely showing
the code as Matt originally presented it.

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