The Authority Problem: Rethinking Prompt Injection Defense Beyond Keywords

Keyword-based prompt injection defenses fail because they address symptoms rather than root causes—attackers simply obfuscate their attacks through encoding and other techniques. This article reframes the problem as one of authorization: untrusted sources attempting to override system-level instructions. By implementing source-aware authority enforcement with explicit trust levels, organizations can move beyond the arms race of keyword filtering to build genuinely robust AI security.