whatis ssh-key
SSH Key
Also known as: public key, private key, ed25519, authorized_keys
A public/private key pair used to log in over SSH without a password. The public key goes on the server; the private key stays with you.
What Is SSH Key in Linux?
ssh-keygen -t ed25519 creates a key pair. Copy the public half into the server's ~/.ssh/authorized_keys (with ssh-copy-id), and the server can verify you hold the private half without it ever crossing the network.
Keys are far stronger than passwords and let you disable password login entirely. Protect the private key with a passphrase and use ssh-agent so you only type it once per session.
Example
ssh-keygen -t ed25519 -C "laptop"
ssh-copy-id alice@serverLearn more about SSH Key
- SSH Keys Explained: Generating, Using, and Not Losing Them Password authentication over SSH is a liability on any internet-facing server. Key authentication is better in every way and takes two minutes to set up. Here is how keys work, which type to generate, and how to manage them properly.
- ssh-agent and Agent Forwarding Explained How ssh-agent holds your decrypted keys, why agent forwarding is convenient and risky, and what ProxyJump does instead.
- SSH Certificate Authorities: Access Control That Scales How SSH certificates replace authorized_keys sprawl, why they solve revocation and host key verification at once, and how to set up a CA properly.
Related tools
- SSH Config Builder Generate ~/.ssh/config host blocks with keys, jump hosts, and connection keepalives.
- ssh-keygen Builder Generate Ed25519, RSA, or FIDO2 security key SSH keys, then install them with ssh-copy-id.