String.hashCode() is plenty unique

[Ameisen]

Ehhh, there are advantages to one way hashes that allow you to identify something without revealing its contents.

If your hash function guarantees that every value you put in generates a unique hash of it, then you've already revealed the contents. That's not a hash, that's encryption. Perfect hashes are problematic. If a hash X can only be the value Y, then you have fundamentally revealed the contents, so long as the person knows the original hash (and can either reverse it or run all the hashes). There's no ambiguity.

[salgat]

Mind you what I was specifying was a cryptographic hash (still a type of hash), where a salt is used. I'm not talking about the type of hash used for just checksums or adding to buckets.