Published onAugust 26, 2026How I Measured the PII Layer in Front of an LLM (And Version One Masked the Label, Not the Tax Number)AILLMsPIIPythonEngineeringGDPRProductionVersion one of my PII layer masked the words "tax number" and let the Greek AFM through. How I measured Presidio, the checksum trap, and the threshold that silently detects nothing. Part 1 of From Prompt to Proof.
