Well, at least it was some hours on near-latest phones with specialized hardware and software (latest and Pixel phones are missing from the study for some reason). Looks much safer compared to Apple's FaceID which was unlocked under 120 seconds with no special hardware attached to the phone (reported by the same Security Lab Tencent): https://www.forbes.com/sites/daveywinder/2019/08/10/apples-i...