How do I enable post-quantum TLS?

Pick your stack. Each guide shows the change, the versions it needs, and a scan box to check the result.

• Post-quantum key exchange on Cloudflare

  What Cloudflare gives you by default, the one setting that caps your grade, and the connection to your origin.

• Post-quantum TLS on AWS load balancers and CloudFront

  How to get hybrid post-quantum key exchange on an Application Load Balancer and on CloudFront.

• Enable X25519MLKEM768 on nginx

  Turn on hybrid post-quantum key exchange (X25519MLKEM768) in nginx with OpenSSL 3.5, then check it with a free scan.

• Enable X25519MLKEM768 in Go servers

  Go's crypto/tls supports X25519MLKEM768 from Go 1.24 and uses it by default. How to make sure your server config keeps it on.

• Enable post-quantum key exchange with OpenSSL 3.5

  OpenSSL 3.5 supports X25519MLKEM768 and enables it by default. How to check your build, configure the groups and verify the result.

• Enable X25519MLKEM768 on Apache httpd

  Turn on hybrid post-quantum key exchange (X25519MLKEM768) in Apache httpd with mod_ssl and OpenSSL 3.5, then check it with a free scan.

• Enable X25519MLKEM768 on HAProxy

  Turn on hybrid post-quantum key exchange (X25519MLKEM768) in HAProxy with OpenSSL 3.5, then check it with a free scan.

• Enable X25519MLKEM768 on Caddy

  Caddy 2.10 offers hybrid post-quantum key exchange (X25519MLKEM768) by default; check yours keeps it, then verify with a free scan.

• Post-quantum key exchange on Azure Front Door

  What Azure Front Door offers for hybrid post-quantum key exchange (X25519MLKEM768), what to set, and how to check it with a free scan.

• Enable X25519MLKEM768 in Java

  Turn on hybrid post-quantum key exchange (X25519MLKEM768) for Java TLS servers, then check it with a free scan.

• "CNSA 2.0 and TLS: what vendors get asked"

  What the NSA's CNSA 2.0 suite means for TLS key exchange, what US government buyers ask vendors, and how to check your public endpoints.

Error messages explained

• "ssh: connection is not using a post-quantum key exchange algorithm"

  What OpenSSH's post-quantum warning means, why it appears, and how to fix it on the server.

• "TLS connections fail when browsers send a post-quantum ClientHello"

  Why some servers and firewalls drop the larger ClientHello that post-quantum key exchange needs, how to spot it, and how to fix it.