SFTP over SSH2: Key based authentication
For SFTP over SSH2, FileZilla utilises the excellent [[ http://www.chiark.greenend.org.uk/~sgtatham/putty/ | PuTTY ]] tools. To allow the use of RSA / DSA key files with Filezilla, you'll need to download 2 more tools from PuTTY: Pageant and (assuming your key file isn't already in PPK format) PuTTYgen.
If your key file is already in PuTTY's PPK format you can skip this paragraph. However if your key is in OpenSSH format, you first need to convert it to PuTTY's PPK format. To do this, launch PuTTYgen and from the menus, select the Import option. Select your key and follow the prompts. Save your private key.
Now run Pageant. In your system tray, you'll see the Pageant icon appear. Right-click the icon and select the option to load your private key. Select your private key (PPK) file. And you're done.
Now simply launch FileZilla and connect to your server using SFTP over SSH2 with a username. Don't forget to close pageant when you're done.
As you may or may not know, FileZilla can be easily carried around on portable media such as a USB stick and used from any PC. This also applies to the PuTTY tools, so if you stick Pageant and your PPK key file on to, for example, a USB stick, you can now access your server from any Windows PC.