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. -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBMGdK9SS9AwzY9LDxAQHdVQQAjwez1skYK8eaClLEq7mCb0V8aPERe/58 3AxH5W9JuaJqWD/nArVLW7HAY4tOM5Sjb2IHZsK3wF29Bd3A/TI0GM5Y1y2vOF9P rNlkM2schf2nfsx7BdfqxWYELxCRUUeZTIagxwWSNMmCbMS22bMiYguVnxHqrjj1 g9n1fCzVDHA= =tpBm -----END PGP SIGNATURE-----
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Ed Carp [khijol SysAdmin] -
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