Well, I don't live in the USA. In my country, we have to own a digital or physic copy to have multiple versions of it. E.G: If I have a game like Mario Bros on my DS, and I downloaded the pirated ROM Mario Bros to stack it on a USB key because it is practice, I can. Same thing for sharing copies, the two people must have a original copy of the game (here it is more an official purchase from the steam Store or KSP webSite)
At least, thanks for your answer.
We can stay in contact if you research also this version... (If you want)