There is a far easier and more effective solution. Iptables has the capacity to do port specific blocking. You're only interested in safe-guarding port 22 (SSH)

There is a far easier and more effective solution. Iptables has the capacity to do port specific blocking. You're only interested in safe-guarding port 22 (SSH). So restrict that port to IP addresses from which you will be connecting to it. I have a static IP, so that's easy. But if you have a dynamic IP, you can make that work too through DDNS or by being less restrictive and sticking to the ip block assigned to your ISP. If you need to handle brute force and hacking attempts over port 80, well, put your password protected stuff in a different directory. Script kiddies always look in the same places =)