The easiest way is to keep track of the text's edit history, keeping a block of edits over time and having them signed by a timestamp authority. The final edit history can then be inspected by some external authority, then signed if the edit history looks human. I have a blog post from 2023 on this topic: https://helbl.ing/Written-Proof-of-Work/
For Google Doc users, you can already inspect the edit history over time to verify that text is written by a human.
For Google Doc users, you can already inspect the edit history over time to verify that text is written by a human.