ed25519 vs RSA keys

ed25519 vs RSA keys
Still generating rsa 2048? It's fine but bigger and slower. ed25519 keys are tiny, faster to verify, and the modern default.
— New key today: ssh-keygen -t ed25519
— Stuck with an ancient device that only speaks RSA: rsa 4096
If you must use RSA, never below 3072. Then disable password auth entirely in sshd_config — the strongest key is pointless if root/password is still open. Swap your key tonight.