You don't want collisions, as the entire point of a hashing algorithm is to _not_ have collisions. I'm not sure what the OP is talking about. What you really w

You don't want collisions, as the entire point of a hashing algorithm is to _not_ have collisions. I'm not sure what the OP is talking about. What you really want for password hashing is a key derivation function, which will generate a random, unique hash slowly.