Definition
Plain language
Checking that a message or person really is who they claim to be.
As stated in the literature
Verification of the origin and integrity of a message or request, typically via cryptographic signatures, tokens, or trusted channels; natural-language instructions carry no such proof of provenance.
Also called: authenticated, unauthenticated
Why it matters: Without a way to prove where an instruction came from, a system has to treat every piece of text it reads as potentially authoritative, which is the root of many prompt-injection failures.
For example, your bank checks a signed token from your phone before moving money, but an AI assistant reading a web page has no equivalent way to verify that a line of text saying "the user approved this transfer" actually came from the user.
Heard on the show
“… The middle one takes three real problems from the morning — an authentication token mismatch, a failed task brief, a gateway downtime — and quietly reframes them as symptoms …”Episode 049 — An AI Agent Reached for Root in Twelve Minutes, Without Being Attacked