What happened to libdvdcss? Is that not a thing anymore?
From what I remember - it’s been a minute - there were many encryption keys that the publishing houses used to encrypt the DVDs released to the wild and they were packaged up in this codec, when they were found.
Make it look like a centralised system initially. Provide a portal to a pre vetted/chosen instance that is accepting new members in their locale/country, that is the same for everyone.
At least they can get in easily to see what it’s about.