For the truly paranoid here are some links that may be of interest:
1. A step-by-step tutorial on making your Pi secure.
http://mattwilcox.net/archives/setting-up-a-secure-home-web-server-with-raspberry-pi/
2. An easy introduction to cryptography. Check out the video, you’ll be amazed!
https://www.crypto101.io/
3. A VPN service with free accounts:
https://proxpn.com/
I also have been using nginx as a reverse proxy and find it works really well but I think there is more that needs to be done. I’m not sure if an attacker gains access to your Pi what else on your network could be vulnerable.
I’m also looking into using Tor:
https://www.torproject.org/
It runs on the Pi. The only cost is allowing some of your internet bandwidth to be used as part of the tor network. The amount used is controllable.
Dan