Intel discussed its vision for the USB Type-C connector during its IDF16 presentation. The biggest changes the company wants to make center on the USB Power Delivery specification, but two new alternate mode specifications with interesting implications for future peripherals were discussed, too: USB Authentication and USB Bridging. Another interesting tidbit involves USB Type-C Digital Audio, a feature that might motivate headphone makers to put a USB Type-C plug on the ends of their cans.
The USB Power Delivery 2.0 specification, refered to as USB PD, is difficult to digest even in presentation slide format, so it might not be a surprise that early manufacturers of USB Type-C cables made errors in their interpretation of the standard. As a result, some companies may have created what I'll deem BadPower legacy USB cables, similar to those Google engineer Benson Leung found on Amazon. Thankfully, Intel has now provided some clarifications in the specification and modified its compatibility testing guidelines. Those changes should improve OEM comprehension, and they could remedy future compatibility problems.
It appears as though Intel is looking to make USB power delivery more consumer-friendly, too. A feature called "Fast Role Swap" lets users unplug a power delivery device (like a wall plug) without necessarily disrupting power to USB devices connected to a hub, for example. Instead, another connected device like a laptop with an alternate power source can step in and supply power to the connected peripherals. USB Type-C may be smart enough to become an international charging standard, too. The International Electrotechnical Commission is dedicating a working group, PT63002, to reviewing and commenting on the USB PD specification.
With the new USB Authentication specification, free USB power stations at airports might go the way of the dodo. USB Authentication performs X.509 PKI path-validation of point-to-point devices over the USB PD configuration channel (CC) or USB data channel. With authenticated USB devices, it becomes possible for hosts to reject devices, or devices to reject hosts. At the airport, that feature might mean getting billed for charging your phone, or outright denied power when you plug in. More consumer-friendly uses for the technology might be a standardized way for secure USB Flash drives to validate a host before they unlock, or a method for hosts to prevent employees from compromising their corporate networks by plugging in unauthorized flash drives.
While USB Authentication is exciting from a device security perspective, it doesn't work with devices like USB hubs yet. That's where the USB Bridging specification plays a role. Instead of a hub performing USB Authentication of an attached device on its own, USB Bridging lets the hub pass information about the device directly to the host so that it can perform USB Authentication. In this way, the host is not required to trust any external peripherals—a desirable security feature.
USB Digital Audio also played a major part in the IDF presentation. Intel is trying to let the device industry migrate away from analog headphone and microphone jacks with the USB Digital Audio specification. The most likely real-world features we'll see from USB Digital Audio appear to be allowing manufacturers to add support for smart audio gear with distinct power states and content-protection algorithms to prevent audio tampering from host to audio output.