A Practical Approach to Putty SSH Key Setup

  • 20/11/2025
  • 3 minute read
creating an SSH key with PuTTY for secure server access

Create an SSH Key Using PuTTY (Step-by-Step Guide)

Using SSH keys instead of passwords greatly improves security when connecting to a remote server. If you’re using Windows and prefer PuTTY, you can generate an SSH key pair quickly by following the steps below.

Tip: SSH keys protect against brute-force login attempts and should always be used instead of passwords whenever possible.

Step 1 — Download and Run PuTTYgen

To begin, download PuTTY or PuTTYgen from the official website:

Download PuTTY

PuTTYgen interface showing SSH key generation process

Step 2 — Generate an SSH Key Pair

Open PuTTYgen and click the Generate button to create a public and private key pair.

Generate SSH key button in PuTTYgen

Move your mouse inside the window to add randomness during key creation.

SSH key entropy generation example

Step 3 — Save Your Keys

  1. Save the private key (.ppk file) — required for authentication
  2. Save the public key — for server installation
  3. Optional: Set a key passphrase for added protection

Saving private and public SSH keys in PuTTYgen

Warning: Never share your private key. Store it securely and create backups.

Step 4 — Add the Public Key to Your Server

Copy the public key from the field labeled:

Public key for pasting into OpenSSH authorized_keys file

Then add it to:

~/.ssh/authorized_keys

Adding SSH public key to authorized_keys

Step 5 — Configure PuTTY to Use the Private Key

  1. Open PuTTY
  2. Go to: Connection → SSH → Auth
  3. Select your .ppk file

Configuring PuTTY authentication using SSH private key

Step 6 — Connect to the Server

Enter the server IP address under the Session tab and click Open to start the connection.

Connecting with PuTTY after SSH key configuration

Note: You can reuse the same SSH key on multiple servers by adding the public key to each one.

Frequently Asked Questions

What is an SSH key?
An SSH key is a cryptographic key pair used to authenticate securely to a remote server without using a password. It consists of a private key (kept on your device) and a public key (stored on the server).

Why should I use SSH keys instead of passwords?
SSH keys are much harder to brute-force than passwords and reduce the risk of credential theft. They are considered a best practice for secure server access.

Can I use the same SSH key on multiple servers?
Yes. You can reuse the same SSH key by adding the public key to the authorized_keys file on each server you want to access.

What happens if I lose my private key?
If you lose your private key and have no backup, you will no longer be able to connect using that key. You will need console or panel access to remove the old key and add a new one.

Do I need a passphrase for my SSH key?
A passphrase is optional but recommended. It encrypts your private key on disk, adding an extra layer of protection if your device is compromised.

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