On: Most software already has a “golden key” backdoor:...

[natch]

That's why updates only happen when the user accepts the update after authenticating themselves.

[DavideNL → natch]

Exactly, that's the part i don't understand yet...

Why doesn't Apple create a mechanism which "only allows updates to be applied after the correct pin is entered"? Then, an update created by the FBI, which would disable security mechanisms, could not be installed (without knowing the correct pin).