In theory, biometric authentication is the most secure way to protect computers, devices and resources - but in practice, that depends very much on the implementation. Fingerprint recognition is the most popular form of biometrics that is currently in wide usage, but it's far from invulnerable. Apple's Touch ID scanner in the iPhone 5S was hacked one day after its release. Android fingerprint scanners have flaws that put users at risk. Biometrics is probably the future of authentication but it still has a way to go before it's perfected.