(I just asked this question on "cryptography SE" and was suggested to ask it here instead)
EDIT I just realized my question is mostly a dupe of: Prevent denial of service attacks against slow hashing functions?
If someone chooses bcrypt isn't the server(s) particularly exposed to a DoS attack that would try to max out the CPU?
If we take, say, a webserver: even if it has a gigantic network bandwith it looks like remotely hammering the server with HTTP POST login requests could give the CPU a hard time.
If the server doesn't rate limit anything it looks like even from a single machine / IP it wouldn't be too hard to force the serve into doing lots of computation.
Is this something to worry about (for example do you need to add some kind of special rate-limiting firewalling specifically taking "remote bcrypt attacks" into account) or am I just being paranoid here?