Fingerprint sensors are all the rage these days on premium smartphones. You will not find a new high-end device launching without one. Even mid-rangers and low-end handsets are starting to offer this feature. That is, as long as they are not running Windows.
Fingerprint sensors are found on Android handsets and iPhones, but not on Windows Phone or Windows 10 Mobile devices. That is, in part, because Microsoft has not implemented support for this feature in its operating system. However, that is soon about to change.
Windows 10 Mobile will gain fingerprint sensor support this summer, according to a WinHEC presentation. This will be introduced as part of Windows Hello, and Microsoft says that it is able to recompile the same driver that is used on Windows 10 to work on the ARM-designed Windows 10 Mobile too.
The best approach when it comes to offering a fingerprint sensor is integrating it in the device itself, but Microsoft will also give hardware makers the option to offer it as a peripheral. I'm not sure if this is something that we will ever see on consumer devices, as users expect these sort of features to work without any accessories attached.
Microsoft also notes that there will be both touch and swipe support for fingerprint authentication. The former is the preferred and recommended option, as it works better in real life. If manufacturers want to implement a touch sensor, Microsoft recommends ones that measures 10 by 10 mm. A square sensor is not ideal for front positioning, so we may see vendors embracing other shapes.
We will have to wait until this summer for Microsoft to roll this feature out, presumably around the same time its Windows 10 Anniversary Update debuts and, hopefully, test it on some new hardware.