Actually, that wouldn’t work.I don’t need the small .exe to extract the game data included in the .bin files.
For some time they used password-encryption on the .bin files, but their password generation algorithm has been found and published quickly. So they decided to just dump the whole password-encryption thing.
You don't need a password, they just need to exclude data from the whole installation files, lets say 50 megas out of it, and let us download that missing megas when the game launch.
No password needed since the installation will be corrupted without the last data.
Plus really, if you CAN download then it means you ordered, and people who want to pirate the game will already find ways for that ... so basically they just punish the honest costumers..