BUILDING A POST-QUANTUM CERTIFICATE AUTHORITY WITH MERKLE TREE CERTIFICATES

Summary from the TLDR IT newsletter

Cloudflare is becoming a certificate authority that issues Merkle Tree Certificates for free, and it is targeting Chrome's quantum-resistant root store in early 2027. Post-quantum signatures are about 40x larger than classical ones, so MTCs batch many certificates under a single CA signature and build transparency logging into issuance. In a Chrome experiment covering 50% of Beta users, the lightweight MTC format already made handshakes 9% faster.