> Jim Choate[SMTP:[EMAIL PROTECTED]] > > On Mon, 22 Apr 2002, Trei, Peter wrote: > > > The defining difference between the two is that if you know the > > algorithm and seed, the output of a PRNG can be reproduced, > > at a different time, place. or both. There are circumstances in > > which this is very much a desired quality. > > Actually you left something out, the PRNG by definition must have a > modulus of repetition. At some point it starts the sequence over. > As usual, Jim is wrong. There are deterministic systems which never repeat. For example, there is an algorithm which will give you the nth digit of pi. If I use this as my PRNG (one way I could seed it would be to use key to pick a starting point) how long does Jim think it will run before it repeats??
Exactly what is the Choatian definition of a PRNG which requires it to repeat, anyway? > In general, this is -never- a desired quality and is the primary > distinction between the cost-utility of PRNG's versus RNG's. > Agreed it's not a desireable property, but it's not always present, as I demonstrate above. It's the 'primary distinction' only on ChoateWorld, of course. > And on another statement by somebody about hardware v software RNG's: > > If you can't develop a RNG in software (ie you'd be in a state of sin), > what makes you think you can do it using -only- digital gates in hardware? > You can't. > Choate is the only one who has said anything about using "-only-" digital gates. You can build analog devices out of silicon, and get Johnson noise from resistors or diodes. You can also build radiation detectors in silicon, though in the absence of a supplied radiation source your data rate will be low (Tim should be able to confirm this). It really bugs me that we have to keep correcting Choate's nonsense - but we have to, lest the less experienced take his views as reasonable. Peter Trei Disclaiimer: The above is my opinion, not neccesarily my employer's.
