SSH keys without the mystery

NOVEMBER 2026 / FIELD GUIDE

Public-key SSH proves you possess a private key without sending that private key to your server.

Generate a key pair on your laptop

ssh-keygen -t ed25519 -C "my-laptop"

Use a passphrase. Your public key can be copied to a server; your private key must remain private.

Install your public key on the Pi

ssh-copy-id learner@linuxlab.local

Or add the contents of the public .pub file to ~/.ssh/authorized_keys on the Pi.

Verify it works

ssh learner@linuxlab.local

Keep an existing session open while changing SSH settings. Validate changes with sudo sshd -t before restarting the service.