As someone who worked on “prompt injection” before it was called “prompt injection” for an (unfinished) phd…

yeah there is only one surefire 100% fix for “prompt injection”: use deterministic solutions ie not machine learning.

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addendum in case someone tries to make this commonly made point -- i don't use deterministic here to mean "i've pinned the ML model weights after training". i use it in reference to the probability theory stuff of training/models (the boring and complicated maths stuff).