In documentation String.hash for iOS it says:
You should not rely on this property having the same hash value across releases of OS X.
(strange why they speak of OS X in iOS documentation)
Well, I need a hasshing function that will not change with iOS releases. It can be simple I do not need anything like SHA. Is there some library for that?
There is another question about this here but the accepted (and only) answer there simply states that we should respect the note in documentation.