Let’s Encrypt works toward post-quantum certificates at web scale

Let’s Encrypt describes its plan to implement Merkle Tree Certificates (MTCs) to provide post-quantum-safe authentication for the Web PKI, outlining how MTCs work, required infrastructure changes (issuance, ACME, revocation, transparency), an expected staging target in late 2026 and production by 2027, and advising operators to enable hybrid post-quantum key exchange (X25519+MLKEM768); the piece is an informational update on standards and deployment rather than an incident report.