Last Friday I spent some time in a discussion with senior members of Apple’s engineering and security teams. I knew most of the technical content but they really clarified Apple’s security approach, much of which they have never explicitly stated, even on background. Most of that is fodder for my next post, but I wanted to focus on one particular technical feature I have never seen clearly documented before; which both highlights Apple’s approach to security, and shows that iMessage is more secure than I thought.
It turns out you can’t add devices to an iCloud account without triggering an alert because that analysis happens on your device, and doesn’t rely (totally) on a push notification from the server. Apple put the security logic in each device, even though the system still needs a central authority. Basically, they designed the system to not trust them.
Rich takes a very interesting look at iMessage security. Basically, saying iMessages are encrypted end-to-end is not the entire story. There's more going on that I, honestly, didn't expect. It might be a bit technical for some people, but this is definitely worth reading.