Re:Random Number Generator Recommendations for Applications
by cbsmith on Wednesday May 31, 2023 @01:12PM
(#36140805)
> Hear hear. There is, indeed, no such thing as running out of entropy in a modern PRNG's state.
Yes, of course. PRNG's are about producing random data from a seed. But /dev/random & /dev/urandom isn't just a PRNG.
> What we really want is to always have an RNG-seeded PRNG, and to always use the PRNG not the RNG.
Which is effectively what is going on with /dev/random & /dev/urandom
Re:Random Number Generator Recommendations for Applications
by tptacek on Wednesday May 31, 2023 @02:08PM
(#36141593)
At the point where you're simply equating /dev/random and /dev/urandom, you're no longer really disagreeing with anybody here. The only difference between the two is that /dev/random keeps a metric on how many bits its vended, and blocks waiting for rekeying when that metric gets too high. That's more or less a nonsensical thing to do.
Hear hear. There is, indeed, no such thing as running out of entropy in a modern PRNG's state.
> I don't think this "PRNG" vs. "RNG" distinction is doing us much good.
But it's still nice to seed and periodically reseed a PRNG w/ entropy from an RNG. So there is a distinction between PRNG and RNG to be made, and we should make it. What we really want is to always have an RNG-seeded PRNG, and to always use the PRNG not the RNG.