Apple has ditched Touch ID for Face ID in its new iPhone X, enabling users to authenticate themselves - including for Apple Pay and apps that support the feature - simply by looking at their handsets.
To make an instore payment, users double click the button on the side of the phone, look at it and then hold it against the contactless reader.
Face ID works by projecting 30,000 invisible infrared dots when the user looks at the phone, checking the pattern against a stored image in real time. Data is stored on the handset.
Apple insists that the technology cannot be tricked by photos or even masks and that it is smart enough to recognise users if they wear a hat or grow a beard. Data is stored on the handset.
The chances of a stranger unlocking a phone with Face ID are put at one in one million, compared to one in 50,000 for Touch ID.
Apple's confidence in its facial recognition tech contrasts with rival Samsung. In March, after reports that the new Galaxy S8 could fooled by photos, Samsung confirmed that it would rely on fingerprint and iris recognition for payments.