How to Create SSH Keys with PuTTY on Windows

To create and use SSH keys on Windows, you need to download and install both PuTTY, the utility used to connect to remote servers through SSH, and PuTTYgen, a utility used to create SSH keys.

On the PuTTY website, download the .msi file in the Package files section at the top of the page, under MSI (‘Windows Installer’). Next, install it on your local computer by double clicking it and using the installation wizard.

After the programs are installed, start the PuTTYgen program through your Start Menu or by tapping the Windows key and typing puttygen. The key generation program looks similar to this:

PuTTYgen initial screen

You can customize the Parameters at the bottom if you like, but the default values are appropriate in most situations. When you’re ready, click the Generate button on the right-hand side.

You might be prompted to “generate some randomness by moving the mouse over the blank area”. This randomness, known as entropy, is used to create keys in a secure fashion so that other people can’t reproduce them.

PuTTY generate entropy

When the key is generated, you’ll see the public key displayed in a text box. Copy this into your clipboard now if you plan to add it to your DigitalOcean account or to servers. Be sure to scroll within the text area so you copy the entire key.

PuTTY new key

Click the Save private key button and select a secure location to keep it. You can name your key whatever you’d like, and the extension .ppk will be automatically added.

Working with PuTTY’s Public Key Format

You can click Save public key as well, but take note: The format PuTTYGen uses when it saves the public key is incompatible with the OpenSSH authorized_keys files used for SSH key authentication on Linux servers.

If you need to see the public key in the right format after the private key has been saved:

  1. Click the Load button.
  2. Navigate to the private key and open it.

The public key will be redisplayed again.

Click the Save private key button and select a secure location to keep it. You can name your key whatever you’d like, and the extension .ppk will be automatically added.

Working with PuTTY’s Public Key Format

You can click Save public key as well, but take note: The format PuTTYGen uses when it saves the public key is incompatible with the OpenSSH authorized_keys files used for SSH key authentication on Linux servers.

If you need to see the public key in the right format after the private key has been saved, either:

  • Click the Load button
  • Navigate to the private key and open it.

The public key will be redisplayed again.

Now that you have your generated key pair saved on your computer and ready to use, you can: