L2J Server

I am trying to make a *addon* at gameserver that will ask for a password when you start *l2jserver.jar* any idea?

For what purpose, may i ask ?

Making a server with four other guys, but the dedicated server is at their names, so i need to have some protection I allready encrypt and convert l2jserver.jar to a locked exe but my problem is that i want to add a password prompt at start.
And i think that this is a good idea for developers, they will be able to have a guarantee from admins etc...
Thanks in advance...