[ninkendo]

Even if you used such a bijective hash, your hash table would have to have 2^32 available buckets in order for the hash match to be all you need for lookup. Or 2^64 for 64-bit… which is why nobody really does this. (And if you did this, why even hash the input? The input integer could just be the key, and you’re basically using a really big sparse array.)

[superjan]

I agree that for standard hash tables this won’t work. However, I recently read about “Ideal Hash Trees” [0], that preserves the entire hash. That design also requires all bits to be “random” because it lacks the usual prime division.

[0] https://lampwww.epfl.ch/papers/idealhashtrees.pdf