Re: "random" number seeds vs. Netscape

At 12:29 PM 9/24/95, Ed Carp [khijol SysAdmin] wrote:
....
>I learned the hard way - keep the transmitters away from a reverse-biased
>doide acting as a noise generator.  Only until I examined the output did
>I realize it wasn't random.  I fixed it, though, by looking at the output
>and testing its randomness.
....
Very interesting. I wouldn't be too sure that a transmitted signal at a
single frequency is the only signal that an opponent could use to bias your
random numbers. How do you "test for randomness". I think that signal to
noise arguments, phrased in terms of entropy, can protect you against
unknown and unwanted signal. (Ironically you want a very low signal to
noise ratio!) Perhaps you merely take n/(S/N) bits from the HRNG when you
need n bits and run them thru MD5. Here S is the signal strength of the
maximum plausible unwanted signal, and N is the noise of the diode.

I encourage both diode theorists and information theorists to quibble with
the above formula!

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> Very interesting. I wouldn't be too sure that a transmitted signal at a
> single frequency is the only signal that an opponent could use to bias your
> random numbers. How do you "test for randomness". I think that signal to
> noise arguments, phrased in terms of entropy, can protect you against
> unknown and unwanted signal. (Ironically you want a very low signal to
> noise ratio!) Perhaps you merely take n/(S/N) bits from the HRNG when you
> need n bits and run them thru MD5. Here S is the signal strength of the
> maximum plausible unwanted signal, and N is the noise of the diode.

I tested for randomness by looking at the distribution of random numbers 
over the range I was drawing random numbers from.  If it didn't look 
random, it wasn't ;)
- --
Ed Carp, N7EKG    			Ed.Carp@linux.org, ecarp@netcom.com
					214/993-3935	voicemail/pager
Finger ecarp@netcom.com for PGP 2.5 public key		an88744@anon.penet.fi

Q.	What's the trouble with writing an MS-DOS program to emulate Clinton?
A.	Figuring out what to do with the other 639K of memory.

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