Just what are QR codes useful for? Machines, not humans. QR codes were developed for manufacturing, so machines could identify and handle objects. And that’s where they work, and work well. Where they don’t work is when an artificial step of human interaction is forced, its always one, two or more unnecessary steps for a human to do, mimicking a machine.
Berg just launched a film showing some of there thoughts for extending that machine automation into the everyday world.
One of the key thoughts I take away is, let the machines talk to each other - minimise human action. I particularly like the qr code reader that hides the camera display - which is unnecessary. Of course theres lots of other potential machine communication possible outside of human detection, thinks like NFC and scanning codes requires a human intent, theres other possibilities such as audio signals, radio waves, etc that may well allow devices to hear where they are too. All these time and place signals will give your actions a real context and linked to cloud - an index of actions and objects around you.
As devices get more powerful the ability to recognise objects and decode the real world will only get close to human abilities, negating the need for explicit markings and digital signatures.