Earlier quoted context omitted.
The paper suggests some of the attack suffixes are quite legible, but if you look at the example screenshots, some look like machine generated gibberish with tons of special characters. This is quite different than the human generated "jailbreaking." It seems tricky to defend against without resorting to drastic measures (like rate limiting users that trigger tons of "bad" responses, or chopping off parts of prompts…
You could also do some adverserial training (basically iteratively attempt this attack and add the resulting exploits to the training set). Research in machine vision suggests this is possible, and even has some positive effects, but it significantly degrades capabilities.
On a train/test/eval split. But the degradation is lower on OOD data. Which suggests perhaps the degradation is merely "less overfitting".