Over at Architectures of Control I find this posting about a patent application from Apple that points out a means of securing hardware by limiting which battery chargers are allowed authorized to work with the device. I have had quite a family of ideas along these lines over the years. Most of these emerged from slew of wonderful standards stories. You see you can always use non-standard as a means of service denial. The example most of us have seen are the plugs in hotels to make it more inconvenient to steal the hair dryer; a historical example is adopting a non-standard railroad gage or bullet to make an invading army’s life more difficult. My favorite story of this class: when they build the world trade center some vendor convinced the contractor to use light bulbs during the construction period that twisted into the sockets the wrong way, counter-clockwise. Nominally that was to prevent the workers from stealing the bulbs but to my mind it was a great way to assure vendor lock-in.
The Apple scheme involves having the charger handshake with the charging subsystem in the device to see if it’s authorized. It’s notable that the charging subsystem’s computer(s) can be kept closed and proprietary while leaving the rest of the system and open platform. Obviously you could do something similar in the graphics chip or the network controller, i.e. any where you have a reasonable smart interface chip. I mean, some of the printer manufactures even do it with their ink cartridges.
There are plenty of variations on this idea. The coffee shop DHCP sign-in rituals are an example. Airports and other public spaces could have lots of non-standard plugs and then rent adapters which grant visitors access. IT managers could have non-standard network connectors to help control access to their infrastructure by building visitors. We can put a lot of wit into a very small package these days; and we know, form the counter-clockwise light bulbs, that people love to get increased control over the littlest things.