How iOS Security Really Works
https://developer.apple.com/videos/play/wwdc2016/705/
Excellent overview of iOS security. Covers off ATS, the secure enclave, the true value of untethered jailbreaks ($1m!). Not super technical, but detailed and accessible.
[this has been sitting in my drafts since.... WWDC was on. But the session is awesome, so if you've not seen it, watch it!]
