Root Causes 661: What Will Happen with eIDAS and MTC?

TLS certificates from CA/Browser Forum CAs are not the only server certificates in the WebPKI. eIDAS QWACs are treated as server certificates by the major browsers. We see clear progress toward post quantum cryptography (PQC) for TLS by way of the Merkle Tree Certificate (MTC) architecture. But what is the path to PQC for eIDAS? We examine this question.