I'm working on a server which eventually supposed to send data to some clients (also self implemented).
The data must be secured.
One option is to implement a regular HTTP protocol and forcing the clients/server to use a VPN connection.
Another option (might reduce costs) is to encrypt my data (just encrypt the payload or use HTTPS).

I read lot's of stuff, but I still not sure I understand the differences in:

1. Level of security
2. Performance

Thanks