Although the Face ID is faster for iPhone 's XS and XS Max, the security system seems to be completely fooled by one twin. If you have brother Doppelganger, you may only use passcodes.
How effective face ID distinguishes between these two:
Forgery of face ID
According to Apple, the probability that a random person can unlock a mobile phone with his face will be 1 / 1,000,000. This feature will not be deceived by photos like Samsung 's face recognition technology, but the human face is an exception.
Last year, a twin couple set tried to deceive a face ID with mixed results. Some twins could not fool that function, but others can. Some hackers were able to deceive the Face ID with an inexpensive mask. In other words, Face ID is safer than Touch ID, but it is not yet perfect.