Only issue with that is security. It would be very easy to steal passwords. It would be BAD. It's not just the password for an alias, some people use the same password for their emails and a bunch of things. The current system is not much safer, since it only relies on trusting the hosts. It's a lazy way to "fix" the problem. This issue would be (from what I hear) pretty easy to fix, but you'd still have to update/replace the whole biller, fix subgame/move everything to ASSS, and update the client.