When you click on the Create Key button the following dialog is displayed. This dialog has controls that allow you to create an SSH private/public key file that can be used in a secure SSH connection that utilizes key authentication.
The creation process creates a single private key file that you should safeguard with great care. Do not share this file with anyone. The process also creates three public key files. These public keys are suitable for SSH1, SSH2, and OpenSSH type servers - the file names are formed using the name you specified and appending a corresponding extension. Check with the system administrator for the FTP site for the type of public key file required by a particular server.
See these guidelines for more information on creating a useful private/public key file.
