I mean it depends, is number of possible answears per prompt known? If so, can we even realistically calculate number of possible prompts? AFAIK ChatGPT answears even tho there is a gramatical mistake in your sentence, does that affect answears/is that considered a new prompt? Ok, let's say you feed all N possible answears in and make a rainbow table of hashes. Sha is basically random (not really, but lets not go there), after I generate my text using AI (which would get flagged by your detection system) and change few letters/words here and there, your whole Sha rainbow table becomes useless - right? I could be totally wrong, but I don't see Sha as a way to solve this problem, because of these complications :/