On 7/18/12, Karl Auer <[email protected]> wrote: > I don't understand the professed need for provable randomness. Without a > number *space* to provide context, randomness is inherently > non-provable. The whole point of the randomness of those 40 bits of ULA > infix is that any number is as likely as any other number. Someone,
When numbers are selected by choosing a random value; certain ratios of bits set to "1" are more likely to occur than other ratios of bits set to "1". A random generator that is operating correctly, is much more likely to emit a number with 50% of the bits set to 1, than it is to emit a number with 0% of the bits set to 1, given a sufficient number of bits. If the ratio is inconsistent by a sufficient margin, and your sample of the bits is large enough in number, you can show with high confidence that the number is not random; a 1 in 10 billion chance of the number being randomly generated, would be pretty convincing, for example. Removing the temptation by excluding the small number of choices with 90% - 95% of the bits set to 1 may eliminate future problems caused by an early "accident"/"error" in assigning the initial ULA, compared to the minor inconvenience of needing to run the ULA generator one more time to get an actual usable range. > somewhere, is eventually going to get 10:0000:0000, someone else will > eventually get 20:0000:0000 and so on. And they are just as likely to > get them now as in ten years time. That is extremely improbable. If you generate a million ULA IDs a day, every day, it is expected to be over 1000 years before you generate one of those two. -- -JH
