How To Set Up SSH Keys on Ubuntu 20.04

🔑 How To Set Up SSH Keys on Ubuntu 20.04

SSH keys provide a secure way to log into your server without a password. This guide covers creating an SSH key pair and configuring key-based authentication.

1Generate SSH Key Pair

On your LOCAL machine:

ssh-keygen

Press Enter to accept the default location. Optionally set a passphrase.

2Copy Public Key to Server

Using ssh-copy-id:

ssh-copy-id username@remote_host

Alternative method:

cat ~/.ssh/id_rsa.pub | ssh username@remote_host "mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys"

3Test SSH Key Login

ssh username@remote_host

✅ If you connect without a password prompt, SSH key authentication is working!

4Disable Password Authentication

⚠️ Only do this after confirming SSH key login works!

Edit the SSH configuration:

sudo nano /etc/ssh/sshd_config

Set these options:

PasswordAuthentication no
PubkeyAuthentication yes

Restart SSH:

sudo systemctl restart ssh

🎉 Your server now uses secure SSH key authentication!