This is a rumour we're certainly hoping is true - Apple has filed a patent that turns your Apple Watch screen into a Touch ID sensor. The feature was spotted by Patently Apple, who often delves into Apple filings to extract juicy details.

While we're seeing a lot of phones with under-display fingerprint readers now, the move would require quite a step-up in tech because of the diminutive size of the watch.

Obviously Apple has a lot experience with Touch ID sensors but not with them under the display.  

Apple has filed stacks of forward-looking Apple Watch patents and interestingly one theme is the moving of antenna out from the actual watch into the band, presumably for better reception.

Could Touch ID make its way to the Apple Watch image 2
Patently Apple

However, we're not sure how that would work with Apple's policy of completely interchangeable bands. It would most likely be quite a way off anyway, possibly looking forward to a time when we have a 5G-enabled Apple Watch in a few years. 

On the Touch ID information in the filing, the patent notes that "the display may provide an image or video output for the watch body 100. The display may also provide an input surface for one or more input devices such as a touch sensing device, force-sensing device, temperature sensing device, and/or a fingerprint sensor."