The State of Post-Quantum Cryptography: May 2026
Post-quantum cryptography is no longer a standards exercise. ML-KEM key exchange is the default in every major browser and in OpenSSH. RHEL 10 ships with post-quantum TLS and SSH enabled out of the box. DigiCert is issuing ML-DSA certificates today. But “available” and “deployed” are not the same thing. Key exchange is largely solved. Authentication — the part where certificates, signatures, and trust chains live — is not. The gap between what the standards define and what production systems can actually verify is where most of the engineering work remains. ...