Among other changes 10.4 adds post-quantum keys (composite ML-DSA 44 and Ed25519), not enabled by default.
When pq key agreement was added in 2019, it took almost 3 years for it to become enabled by default. This isn't criticism, just an observation. I don't have a pressing need for pq sigs. Always happy for new OpenSSH releases though!
lousken•26m ago
Is hmac-sha1 and umac-64 still enabled by default?
throw0101a•1h ago
* https://www.openssh.org/releasenotes.html#10.4