The flaws in some smartphones' biometric security

While biometrics can offer added security, two separate issues highlight limitations of the technology, especially when used as the sole means of locking a smartphone and user accounts.

Driving the news: Samsung says it is working on a software update for the Galaxy 10 after a user in Britain discovered that using a protective case, in some circumstances, will allow any fingerprint to unlock the device.

• Google acknowledged that the face recognition technology on the Pixel 4 will unlock the device even if a user's eyes are closed. Apple, by contrast, designed Face ID so that a user must be looking at the screen to prevent someone gaining access by pointing a phone at a dead or sleeping owner.

Why it matters: Fingerprint and face recognition can add simplicity and security, when done right. When done wrong, though, they can put users at risk.