I wonder, is it in the realms of possibility for big-budget organizations like the NSA to simply read the UID from the silicon by means of physical analysis (e.g. a scanning tunneling microscope)?
It's very probably not within the realms of practicality just yet, however.
The only issue would be making the process so 100% reliable that you succeed first time, because a single mistake or misunderstanding could trash the single copy you have of the code.
I'm curious now if flylogic or chipworks have done any serious teardown of the 'secure enclave' stuff.
"enough cash and bricked test phones" - the great thing about this, is you can just buy the $650 phones - you can get a thousand of them for less than a million dollars, which probably is under your typical line managers budget in the NSA techOps group.
And, lets be realistic, Apple isn't trying to defend against the NSA or Nation States, just your average hacker without access to $100mm+ in hardware.