How to Secure SSH Access on Your Linux VPS

This guide shows you how to protect your VPS from attackers by setting up SSH keys, disabling root login and changing the SSH port.

1. Create SSH key

First, create an SSH key pair on your local PC.

Windows (PowerShell)

ssh-keygen -t ed25519

Linux / macOS (Terminal)

ssh-keygen -t ed25519

Confirm the default path with Enter and optionally set a passphrase for additional protection.

Two files are created:

• ~/.ssh/id_ed25519 – your private key (never share this!)
• ~/.ssh/id_ed25519.pub – your public key (this goes on the server)

2. Upload public key to the server

Upload from Linux / macOS

ssh-copy-id root@YOUR_SERVER_IP

Upload from Windows (PowerShell)

type $env:USERPROFILE\.ssh\id_ed25519.pub | ssh root@YOUR_SERVER_IP "mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys"

3. Create a new user (optional)

Optionally, you can create a separate user instead of logging in as root.

adduser myuser

Grant the user sudo rights:

usermod -aG sudo myuser

Copy the SSH key to the new user:

mkdir -p /home/myuser/.ssh
cp ~/.ssh/authorized_keys /home/myuser/.ssh/authorized_keys
chown -R myuser:myuser /home/myuser/.ssh
chmod 700 /home/myuser/.ssh
chmod 600 /home/myuser/.ssh/authorized_keys

4. Disable root login and password authentication

Open the SSH configuration:

sudo nano /etc/ssh/sshd_config

Find and change the following line:

PasswordAuthentication no

If you created a separate user in step 3, you can also disable root login:

PermitRootLogin no

Save with Ctrl + O, close with Ctrl + X and restart the SSH service:

sudo systemctl restart sshd

5. Change SSH port

By default SSH runs on port 22. Changing this reduces automated brute-force attacks.

Open the SSH configuration:

sudo nano /etc/ssh/sshd_config

Find the line #Port 22 and change it to:

Port 2222

If you are using UFW, allow the new port before restarting:

sudo ufw allow 2222/tcp

Restart the SSH service:

sudo systemctl restart sshd

From now on, connect with:

ssh -p 2222 root@YOUR_SERVER_IP

Summary