Hidden Reasoning Is the New Security Boundary: 315,320 Decoded Reasoning Blocks & Persistent Prompt Injection in Agentic Rollouts
A research technique reported August 11, 2026 decodes hidden chain-of-thought reasoning blocks across Anthropic, OpenAI, and Google models — 315,320 blocks scraped, 367 PII artifacts and 182 credentials recovered, and prompt injections that persist invisibly inside agentic rollouts. This analysis re-frames the reasoning channel as a first-class security boundary and lays out the five-layer defense stack.