How does a fingerprint unlock a phone?
Fingerprint's Secret Code
How does a fingerprint unlock a phone?
You press your thumb to your phone and — click — it unlocks. No password typed, no pattern swiped. Your phone just looked at your fingerprint and said, "Yep, that's you. Come on in." But how does a slick piece of glass know what your thumb looks like?
First, a quick fingerprint fact: your fingertip is covered in tiny ridges — raised lines that swirl and loop in a pattern totally unique to you. No one else on Earth has your exact fingerprint, not even an identical twin. Those ridges are your body's built-in ID card.
