Why it matters: While Apple's Face ID is, on the whole, pretty secure, it's still not perfect and is especially easy to fool if you have a twin or doppelganger. But a newly discovered patent suggests that a future implementation could improve the system by scanning a person's veins instead of using only their facial features.

PatentlyApple uncovered the patent, titled "vein matching for difficult biometric authentication cases." It highlights the difficulty facial recognition systems have when two faces look very similar---the so-called "evil twin" scenario. We even saw how Face ID could be tricked by masks when the system first debuted on the iPhone X.

Using subepidermal imaging, or vein scanning, could lower Face ID's false positive rate by using the veins in a person's face to confirm their identity. The patent also covers machine learning, which will be used in the system to help distinguish between faces.

This wouldn't be the first phone to use veins as a way of identifying users. LG's G8 ThinQ from last year uses a Hand ID feature. It fires an infrared signal at your palm and creates a map of the veins based on how the hemoglobin in your blood absorbs the IR signal. Sadly, it doesn't work too well, so here's hoping Apple's version is better.

Apple has long been an advocate for dropping the password in favor of biometric security, and the company recently joined the FIDO alliance. But exactly when we might see subepidermal imaging become part of Face ID is unclear---like all patents, there's no guarantee it'll ever become a reality. Don't expect it in the upcoming iPhone 12, but perhaps vein scanning will be part of the iPhone 13.