PuTTYgen is a key generator tool used for creating pairs of public and private SSH keys. This software is one of the components of the open-source networking client called PuTTy.  It can create various public-key cryptosystems, which are principally focused on secure data transmission and digital signature. Although it primarily collects keys in native formats, such as PPK files, users can easily convert them to any file format. PuTTYgen is a completely free program. You can use it from the PuTTy window or download it separately.

How do you use PuTTygen?

As noted, it is a utility used to generate both public and private key pairs for creating SSH keys. Once launched, you will find a Generator button in the dialog box. Clicking on it will start the generating of the keys. What you will do next is to add a unique key passphrase in the Key Passphrase and Confirm passphrase field. Click on the Save Public Key and Save Private Key buttons will allow you to save the keys you generated.

You will then see the text starting with ssh-RSA in the Public key. You can then paste this text into the OpenSSH authorized_keys file field located at the top of the window. Note that you need to copy the entire text to your clipboard by pressing CTRL + C. You will need the key to paste on your clipboard in the public key tool of the control panel or directly on the cloud server.

You can use the RSA key pair you generated with PuTTYgen in two ways. You can use it to assign while creating a new cloud server. You can also use it to assign to an existing cloud server. More than that, you can also load an existing private key file into the memory. Doing so allows you to change the passphrase and the comment before saving it again. You can also make extra copies of the public key. 

Streamlined process

PuTTYgen is a handy networking environment that allows users to generate SSH keys easily. The app simplifies the process of generating new key pairs—both public and private. Moreover, it lets you load existing ones and make changes to them. It is not strictly related to PuTTy. However, PuTTy users will need it to create the SSH keys.