How is that even remotely related?

The Linux implementation I've seen is the Freedesktop implementation that just responds to a user profile flag. There's no cryptography involved, it's just like asking for a room number like the adduser command does.

Edit: well except American states don't flag your operating system as illegal unless they ask for your room number. Canonical and all the other Linux companies really like being able to make money and not spend all of their earnings on lawyers.