The best method is, as always, an anti-privacy method.

Simply track all citizens' writing patterns throughout their life, from cradle to grave, then diff with any given text's signature--you'll know if it was human written or not.

Better--opt in--install a "personal text signature" on your devices, sign things that you wrote yourself with it.

But I suppose that's just like the image provenance chips on cameras.

Either way father fascism is more with us than ever, praise him!