How to use PuTTy to establish an SSH connection using public key authentication:
You entered the public key under Additional Settings > SSH Key when creating your Cloud Server.
Enter the IP address of your Servers in the Hostname (or IP address) field.
Under Category > Connection, click Data.
Enter the username in the Auto-login username field.
Under Category > Connection > SSH, click Auth.
Find Private key file for authentication and click on Browse...
Select the Private Key.
To establish the SSH connection, click Open.
The first time you log in, a warning message appears. Since the SSH server was previously unknown, PuTTy does not have a key.
To allow the connection and save the key for future sessions, click Yes.
The key is verified and then the SSH connection is established.