^ Realistically no ... like you said, if they can see it, they can copy it. Have way more questions than anything like answers for you. What the hell kind of data is this, what's the purpose for it etc etc ? Recently watching some Tiktok type vid on Youtube, SUPER hot girl does it but she pointed out something apparently Iphones have now. Person could take a pic of text like as shown on a projector for taking notes in a classroom and the thing can select + copy it.
Going no further with such ramblings. Honestly though ask the NSA or MI6 or something, am sure they could hook you up in no time flat. Sighs ... though then they'd probably have to kill you. So wouldn't really be much help towards completing your (kinda odd)project.

I <heart> gnu/Linux, Openbox and xdotool ...