Don't worry about that stuff until people actually start to pirate your game.
Hmm.. probably shoulden't have used the word 'pirate'. What I meant is that I plan to have player register for a free account until the 1.0 release, and that key is just to make sure it's that player.
I'll be the bearer of bad news.
Ain't no one going to care about that, let alone should you. No one is going to sign up to a game they know nothing about.
Put it this way, if I downloaded this and seen a "login" screen when I start it up, I would just quit and delete it.
Forget about all that stuff and code your game, stop trying to cater to an audience you do not have. Again, just code and enjoy
Many people do exactly what you are doing, make their first game and think everyone is going to love it and start playing it, they implement such thing as login systems, player database, a website etc etc. Don't fall into that trap, your doing well.