Communication with the Particle cloud is always encrypted. If you set up a webhook from there to call an HTTPS site, as an example, that is of course encrypted.
So, you don’t need to handle the encryption yourself to have secure data movement.
I need it because when the app I’m using was written, we didn’t understand this.
When I compile my app with the aes.h above and the includes listed above, it flashes to a Photon just fine but doesn’t run (SOS 1.). When I compile and run on the Core, it hard resets the instant I try to make an HTTP call (I’m encrypting the payload.)
So, time for me to use a more supported solution, methinks. Don’t make the mistake I did and try to handle encryption yourself unless you know C a lot better than I do.