Let’s Encrypt Adopts Merkle Tree Certificates for Post-Quantum Cryptography

Let’s Encrypt has announced a new approach to post-quantum cryptography for the web’s public key infrastructure (PKI) by adopting Merkle Tree Certificates instead of larger post-quantum signatures to avoid bloated handshakes. The organization plans to begin testing this method by the end of 2026. The initiative aims to make the web’s PKI quantum-resistant without compromising performance. No specific technical implementation details or CVE IDs were provided in the announcement. The focus is on mitigating future threats from quantum computing while maintaining efficiency in certificate issuance and validation.