Thanks for the feedback!!

Technically, you could already host the database on a secondary server. Either way, there has to be a conduit to the application server (which can be exploited). Adding a second host to the setup (for smaller applications), will not make your users happy. Additionally, the DB credentials also are stored somewhere (code or other place). To be honest, I don't know that many applications that use an outside authentication service for the system keys/passphrases. There's always systems like TACACS+, RADIUS, LDAP but in some way, shape or form, they all require a key of their own to confirm and with the key, it's fairly simple to decode the authentication stream and find out the functional credentials. What I meant by password recovery is that if you 'forget' the encryption keys, there's no way of easily changing the keyphrase. I agree that a passphrase on startup sounds a good idea but it still needs to be stored somewhere, even in memory.. Plus, it's preventing a normal startup process. I can't recall any applications that take this approach. Having a compiled application, for instance, to hide the keyphrase is only slightly less effective as it should be fairly easy to pass the same authentication request as the script is using.