&gt; Certificate Transparency-style public ledger for all firmwares that Apple has signed. Refuse an update if the firmware version has not been published to the ledger. This would make these backdooring attempts public, since we can assume people would watch the ledger and ask questions in case of an unknown version being published.<p>That&#x27;s seems like a fantastic idea but without open source firmware I don&#x27;t see how it could be enforced.