Vivo recently took the lead in innovative security for smartphones by becoming the first company in the world to implement in-display fingerprint sensor technology in smartphones.
Placement-wise, the sensor itself will sit betwen themainboard and the OLED panel where it will illuminate the finger. After this, it then processes the beams of light. In fact, Vivo seemingly perfected this technology, as they confirmed that the devices are ready for mass production. Also, expect an announcement in early 2018.
Comparatively, the security runs at the same level as current scanners seen in other flagship devices like the Samsung Galaxy S8. Synaptics, at least, gave this assurance in their own press message.