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evujumenuk | 1 year ago

Maybe I'm misinterpreting something, but… isn't this really about https://en.wikipedia.org/wiki/Perfect_hash_function? "Perfect" doesn't represent a statement of quality here, if that's what you're alluding to.

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Retr0id|1 year ago

No, I mean in the sense given on the page (I should've included the parenthetical in my quote)

> (e.g. a random permutation of all 32-bit integers)

Since they only use bijective primitives, it's trivially "perfect" in the "perfect hash function" sense.

To elaborate further on the definition I was going off (which may well not be what the author meant):

> A PRF is considered to be good if its behavior is indistinguishable from a truly random function. Therefore, given an output from either the truly random function or a PRF, there should be no efficient method to correctly determine whether the output was produced by the truly random function or the PRF.

https://en.wikipedia.org/wiki/Pseudorandom_function_family