I'm opening my SSH to the world on my home based server. I changed the default port. I made the passwords for root and the only manually added user (done at install time) to totally random 64 character passwords which I store on a USB thumb drive.
In addition, I have followed the steps here to restrict outside access to the IP of my blackberry device:
I also disabled root login (though I may re-enable so I can more easily add/remove/edit files using WinSCP as root - especially if I can restrict root login to 192.168.1.105 address???)
Anyways, studying the SSH config file I see an option:
which when changed to 'no' seems to stop login to the SSH server if I don't have a public key. I've tried setting that up before but always had problems with putty on Windows.
My question is, what advantage does PPK provide in addition to SSH? I thought SSH was already secure? Hence Secure Shell? Perhaps I may have misunderstood, that SSH is only as secure as FTP unless you also configure the SSH to use PPK?