How certain is it that a shorter password can’t match the salted hash of a long one? [migrated]

We (collectively) salt passwords, then hash them; maybe even run them through something like PBKDF2 first (depending on how the password will be used).
The end result is that we have a string p and map it to a fixed-length string p’ using … Continue reading How certain is it that a shorter password can’t match the salted hash of a long one? [migrated]