The Channel Question: Post-Quantum Substrate for AI Agent Communication

AI agents now exchange consequential, long-lived data over MCP and A2A. Both delegate confidentiality to classical TLS, and neither mandates post-quantum key exchange, so every agent integration inherits its quantum posture by default. Under harvest-now-decrypt-later, that exposure is already accruing. This paper poses the channel question as an executive decision: who owns the quantum posture of an organization's agent traffic, the architecture that owns it on purpose, and the regulatory clock that is already running.Paper #1 of the PQC for AI Agents Series.