> Message: 7 > Date: Thu, 28 Mar 2002 22:41:31 -0700 > From: "John (EBo) David" > Subject: Re: Random numbers > To: plug-discuss@lists.plug.phoenix.az.us > Reply-To: plug-discuss@lists.plug.phoenix.az.us > > KevinO wrote: > > > > Craig S. wrote: > > a completely random (ok this is impossible in practice ... > > > > You CAN get truly random numbers but it requires a little specialized hardware > > to do it. Make your noise using an analog technique and then sample and > > digitize it. With a little care and not much money it is very possible. > > there was a scientific amirican artical about 10 years ago on building a > chaos white noise random generator usinging a diode operated in it's > unstable region and sampled... They got the thing to sit there and > wonder all over the place. Appearently the dude that made it was able > to get the built for just a couple of dollars at radio shack. You would > likely be able to build it with an old junk radio or TV ;-) > > EBo -- > > --__--__-- > > ok, here is what I understand the definition of randomness to be. It is a arbitrary selection of value between two magnitudes. Now I visualize that varying value as entropy in a bigger picture (after all even though we have a upper and lower bound for the selection of value infinity is much much larger than either bound.) As n in the magnitude tends towards positive and negative infinity this entropy starts to become a neglible factor and we can interpolate values within the bound with a high degree of precision. Now in the physical world we don't have a infinite number of circuits to crunch numbers. So the trick becomes bounding these limits with a large enough value to make the randomness neglible or to sample the value enough times within the bounds to make a determination of what the value is not. Once we know the irrelevant values a determination can be made as to what the value is.Either way determining a new bound or sampling values takes time. So what we want in encryption or selection of random numbers is to make being able to determine the original values so time consuming that the information is either useless by the time the answer is found or the cost of determining the values exceeds what those values are worth. That is the core of a good encryption scheme. Of course as technologies advance so must encryption standards so that the cost of decryption stays higher than the value of the data. I havew tried to cover about 4 pretty deep subjects in two paragraphs. Coupled with the knowledge that I am not a encryption expert (just a knave in the trade) there is much that can be expanded on. But it is at least an insight as to why I made the statment I did about random number selection. Craig S.