Using SSH RSA Keys Securely

I use non-password protected keys for scripted scp/ssh use. It's the only way to do it, IMO. There are a few things I do to keep them safe:

Here an example of an authorized_key entry that limits access to one IP address:

from="" 1024 37 152...(abbreviated)..8541 keyname

Basically: just copy the public key file to authorized_key as usual, then preceed the line with from="IP-address". Wildcards are allowed.

Thanks to Johannes Ullrich