Re:FBI May Demand iOS Source Code, Signing Key
by tlrobinson on Friday March 11, 2016 @02:27PM
(#11268877)
That is in fact how iPhones' encryption works, except the vast majority of users don't set a high-entropy passphrase [1] because a) it's not enabled by default (because of (b) and (c)), b) it's not great user experience, and c) most people don't understand or care.
This is why Apple also implemented the brute forcing protections that the FBI is trying to bypass via a firmware update.
However, I do think that it should be impossible to update the firmware (including via DFU) without either a) the passcode, or b) wiping the phone. If the owner doesn't know their passcode they'll need to wipe the phone anyway. Anyone else doesn't have any business updating the owner's firmware without their permission.
[1] https://support.apple.com/en-us/HT204060 "Change your passcode. Enter a new, six-digit passcode. Or tap Passcode Options to switch to a four-digit numeric code, a custom numeric code, or a custom alphanumeric code"
This is why Apple also implemented the brute forcing protections that the FBI is trying to bypass via a firmware update.
However, I do think that it should be impossible to update the firmware (including via DFU) without either a) the passcode, or b) wiping the phone. If the owner doesn't know their passcode they'll need to wipe the phone anyway. Anyone else doesn't have any business updating the owner's firmware without their permission.
[1] https://support.apple.com/en-us/HT204060 "Change your passcode. Enter a new, six-digit passcode. Or tap Passcode Options to switch to a four-digit numeric code, a custom numeric code, or a custom alphanumeric code"