Biometrics Made Simple: Why Your Fingerprint and Face Make Good Security (and 5 Myths to Ignore)

Every day millions of us unlock a phone with a glance or a fingertip. That's biometrics: using something about your body (your fingerprint, face or eyes) to prove it's you. It feels like a gadget feature, but it's a real security tool, and it's one of the easiest ways for a family to get safer without making life harder.

Why biometrics are worth using

  • They make strong locks painless. People pick short, easy passcodes because typing them 80 times a day gets old. With a fingerprint or face unlock, you can set a longer passcode and still get into your phone in a second.
  • They're very hard to guess. Apple says the chance that a random person could unlock your iPhone with their face is less than 1 in 1,000,000 with Face ID, and 1 in 50,000 for a single finger with Touch ID. Compare that with a 4-digit PIN, which has only 10,000 possible combinations.
  • Nobody can peek over your shoulder. A stranger in line can watch you type a PIN. They can't "watch" your fingerprint.
  • They power passkeys, the password replacement. More and more sites let you sign in with a passkey instead of a password. You unlock it with your fingerprint or face, and according to the FIDO Alliance (the group behind passkeys) your biometric stays on your device and is never sent to the website. Passkeys also can't be phished the way passwords can. Prefer to carry your sign-in on your keychain? A FIDO2 hardware security key like our SecuX PUFido (USB-C) does the same phishing-proof job for supported accounts.
  • They work on doors and drawers too. Fingerprint locks mean no keys to lose, no combinations for kids to forget, and no spare key under the mat.

5 common myths, busted

Myth 1: "My phone sends a picture of my face or fingerprint to Apple or Google."

Fact: Apple says Touch ID doesn't store any images of your fingerprint, only an encrypted mathematical representation that stays on your device, and that Face ID data never leaves your device and is never backed up to iCloud. Modern Android phones are designed the same way, keeping fingerprint data in secure hardware inside the phone.

Myth 2: "Once I set up my fingerprint, my passcode doesn't matter."

Fact: Your passcode is still the master key. Your phone asks for it after a restart, after several failed scans and from time to time for safety. That's why using biometrics is a great reason to choose a longer passcode: you'll rarely have to type it.

Myth 3: "Hackers can easily fake my fingerprint."

Fact: Security researchers have fooled sensors in the lab, but it takes time, skill and a high-quality copy of your print. Everyday thieves and scammers don't work that way. They guess PINs, steal passwords and trick people into sharing codes. After a few failed scans your phone falls back to requiring the passcode anyway.

Myth 4: "If my fingerprint gets stolen, I'm stuck forever."

Partly true, and that's the point. You can't change your fingerprints like a password, which is exactly why well-designed devices keep biometric data encrypted on the device instead of in a company database. Our advice: use biometrics on your own phones, computers and locks, and be choosier about apps or gadgets that want to upload your face or fingerprints to the cloud.

Myth 5: "Anyone who looks like me can get in."

Fact: For almost everyone, no. Apple does note the odds are higher for identical twins, look-alike siblings and children under 13, because their features may be similar or still developing. If that's your household, use a passcode, or use fingerprint unlock instead of face unlock.

Quick tip: turn biometrics off in a hurry

If you ever want your phone to require the passcode, for example at a crowded event or if someone tries to grab it, you can temporarily switch off face and fingerprint unlock. On iPhone, press and hold the side button and either volume button for about 2 seconds, then cancel. Many Android phones have a Lockdown option in the power menu (you may need to turn it on in your lock screen settings first).

Biometric security for the rest of your life

Your phone is just the start. Here are a few fingerprint-powered tools from our Biometric Security collection:

Tips for any fingerprint device: register at least two fingers (one from each hand), keep rechargeable locks charged, keep a backup key or code somewhere safe, and install firmware updates for smart locks when the app offers them.

Sources: Apple Support, "About Face ID advanced technology" and "About Touch ID advanced security technology"; FIDO Alliance, "Passkeys".