Currently, I’m using the latest CentOS, but is not really a CentOS question.

Droplet A:
NGINX acting as a reverse proxy serves https requests

Droplet B:
Apache Tomcat (my java web server) running on port 80.

Historically when I was not on Digital Ocean, I had physical security and I connected over port 80 between my backend servers

At Digital Ocean, there is not a true ‘private’ network. Only private within Digital Ocean’s thousands of clients.

Some people have mentioned the following:

1. IPSec using Strong Swan or something similar
2. Using Tomcat’s cryptography (I’m not sure how fast java is at cryptography)
3. SSL Tunneling (We’ve used autossh for less critical things, but doesn’t feel right here)
4. Running NGINX in front of the tomcat. (Installling another NGINX instance on Droplet B in front of tomcat)

What is the best way to secure and not compromise performance?