Apple admitted from the start that its one-in-a-million figure for the odds that someone other than you could unlock your iPhone X with Face ID comes down substantially when you start facoring in twins and siblings, and users have wasted no time putting it to the test. One Reddit video shows that even non-identical siblings who just look enough alike can fool the face scanning technology. While the second brother’s face wasn’t able to open the iPhone X on several failed attempts, after repeated tries and passcode entries after failure, the second brother adding a pair of black-rimmed glasses did the trick, allowing him to unlock the device.
That leaves the question open as to whether the iPhone X was actually fooled or whether it was trained to recognize the second brother’s face as close enough by all of the repeated failures, and Apple hasn’t shed any light on whether the Face ID technology can be taught to accept a greater degree of variation. Another video shows two half-brothers breaking Face ID, but one of the brothers is 14 and Apple has warned that kids who don’t have “fully developed facial features” will be somewhat problematic for the Face ID scans as well, so that could be a contributing factor.
Siblings aside, others who have tried to beat Face ID with other means have mostly failed. A feature from Wired outlines an intense mask-making process that tried and failed to create a fake face realistic enough to fool the sensors.
Part of the problem with using that method is Apple’s “liveness detection” feature, which requires the user to be looking at the device to unlock it, preventing others from just scanning the person’s face while they’re sleeping or not paying attention. A Gizmodo reviewer was actually able to beat that system, with a colleague proving able to unlock the device using her face while she feigned sleep. The reviewer laid out a couple of possible culprits, speculating that her hooded eyes can look closed when she smiles, possible making Face ID “struggle to understand what’s a grin and what is slumber.” The UV protective layer on her glasses is also problematic, as Apple has admitted that some forms of UV protection can affect Face ID accuracy.