So I've been educating myself on security and just generally learning how things work. I pretty well understand how iMessage encryption work with Apple servers passing out the public key for a given device and the private key never leaving said device. That said - say I have an iPhone, iPad, and a Mac. My understanding is that each has a key pair. Does that mean when someone sends me an iMessage, the device that they send it from makes three copies and individually each one and sends it out? I guess that's the only way that seems secure, but it also seems a little tricky. In all honesty this question has no practical application, I was just curious how it all works.