Much more likely that if camera manufacturers decided to do this, they would each offer a their own proprietary and incompatible image verification scheme, forc

Much more likely that if camera manufacturers decided to do this, they would each offer a their own proprietary and incompatible image verification scheme, forcing implementations to integrate with many different services. Eventually recognizing the problem, they would form a Trusted Imagery Working Group™ to develop a patent-encumbered chip that would need to be licensed for use (available only to invited member organizations), and present in all devices that will create or validate image signatures. Keys from that chip will eventually be extracted, rendering it useless, but industry will be widely reliant on it, with too much inertia to change.