[woliveirajr]

Oh, so we're talking about different things (not exactly with you, but in the conversation)

I was thinking about the number of interactions (or any other tunable parameter) in the same algorithm, like Scrypt or bcrypt or PBKDF2.

Of course, you're completely right on your example: change one for another that increases time just in browser doesn't give any gain. It must be harder to the attacker...