The user name and password and any other information that is entered as part of configuring a user account on an Emu Server exists only on your Emu Server. There is no central server system that stores this information. The security of your Emu Server is your responsibility. For maximum security, choose a user name and password combination that you are not using elsewhere and ensuring your Emu Server is behind a firewall.
When you login to your Emu Server from an Emu Player, a challenge response protocol is used to authenticate you. Your user name and password are not transmitted in any way shape or form either to your Emu Server or to anywhere else.