Instructions
Open WinSCP and click "Session."
Enter the PS3's IP in the "Host Name." You can find the IP address on your PS3 by opening "Settings," then "System Settings," then "System Information" and then checking the IP in System Information.
Enter the user name and password for your PS3. This will be designated by the firmware or OS you are using. Check the documentation for the individual settings if you are unsure.
Click the ".." and choose a location for the secure key to be stored.
Click "Save," and then "Login."