Google’s work on Merkle Tree Certificates (MTCs), now advancing through the IETF’s PLANTS working group, signals more than a technical upgrade — it points to a fundamental rethink of how digital trust is built and delivered.
It signals a structural redesign of digital trust architectures.
Until now, post-quantum cryptography (PQC) conversations have focused heavily on algorithms: ML-DSA, SLH-DSA, key sizes, and signature schemes. While those details matter, they are not the main barrier to adoption. The real challenge is operational — how these algorithms perform when integrated into existing PKI systems at a global scale.
This is where MTCs come in.
PQC is a Scaling Problem
