Nobody can mitigate prompt injection to any meaningful degree. Model releases from large AI companies are routinely jailbroken within a day. And for persistent agents the problem is even worse, because you have to protect against knowledge injection attacks, where the agent "learns" in step 2 that an RPC it'll construct in step 9 should be duplicated to example.com for proper execution. I enjoy this article, but I don't agree with its fundamental premise that sanitization and model alignment help.
Show me a legitimate practical prompt injection on opus 4.6. I read many articles but none provide actual details.
I agree that trying to mitigate prompt injection in isolation is futile, as there are too many ways to tweak the injection to compromise the agent. Security is a layered thing though, if you compartmentalize your systems between trusted and untrusted domains and define communication protocols between them that fail when prompt injections are present, you drop the probability of compromise way down.