SSH is a protocol for connecting to a remote computer (server) and running commands on it securely. Remote resources can be accessed in the usual way, either by specifying a username and password or by using SSH keys. An SSH key consists of 2 files - a private key and a public key. The private key is stored on the user's computer and the public key is hosted on the server.

To create an SSH key in a Windows environment, you should do as follows:

1. Download and run the app puttygen.exe.
2. Select the desired SSH type, RSA (recommended) or DSA and click Generate. Move the mouse in the main window of the app during generation.
3. Enter a comment for the key (e.g. your username) and a passphrase to protect the key.
4. Save the public and private keys on your computer. Don't forget to copy the generated text Public key for pasting into OpenSSH autorized_keys file at the top of the page, because it is needed for pasting it into the authorized_keys files of the servers you want to connect to.

You can use the Putty agent for connection to the server. In the main Session window, enter the server's IP address and port (22 is standard), and in the application settings Connection → SSH → Auth → Crediantials, specify your private key (.ppk) file. In the window that appears, set the username root and the SSH passphrase.