I am testing Erlang and have a few questions related to Security of the Distribution. (There is a lot of mixed information out there) These type of questions come with lots of opinions related to situations, and depends on personal comfort level on the type of data you are dealing with. For the sake of this question, lets assume it is a simple chat server where users can connect to and chat together.
Example Diagram: 
The cluster will be behind a private subnet VPC with elastic-load-balancing directing all connections to these nodes (to and from). The elastic-load-balancing will be the only direct path to these nodes (there would be no way to connect to a node via name@privatesubnet).
My question is the following:
Based on this question and answer: Distributed erlang security how to?
There are two different types of inner-communication that can take place. Either, directly connecting nodes using built in functionality, or doing everything over a TCP connection with a custom protocol. The first is the most easiest, but I believe it comes with a few security issues, and I was wondering based on the above diagram if It would be good enough (Er, okay, Good Enough is not always good when dealing with sensitive information, but there can always be better ways to do everything ...)
How do you secure and Erlang cluster behind a private subnet? I would like to hide the nodes, and manually connect them, and of course use cookies on them. Is there any flaws with this approach? And since a custom protocol using TCP would be the best option, what type of impact does that have on performance? I want to know the potential security flaws(As I said, there is a lot of mixed information out there on how to do this).
I would be interested in hearing from people who have used Erlang in this manner!