Imagine you're standing in line to buy an after-school snack at a store. You step up to the counter and the cashier scans your food. Next, you have to pay. But instead of scanning a QR code with your smartphone, you just hold out your hand so the cashier can scan your fingerprint. Or, a camera scans your face, your eyes or even your ear.

【小题1】 As technology companies move away from traditional password, biometric security, which includes fingerprint, face and voice ID, is becoming increasingly popular.

In 2013, Apple introduced the iPhone 5s, one of the first smartphones with a fingerprint scanner. Since then, using one's fingerprint to unlock a phone and make mobile payments has become commonplace, bringing convenience to our lives. And since lasts year, San-sun has featured eye-scanning technology in its top smartphone, while Apple's new iPhone X can even scan a user's face.

【小题2】 “Bio-metrics, ideally are good.” John Michener, a biometric expert, told tech website Inverse. “In practice, not so much.”

When introducing the new iPhone's Face ID feature at Apple's Keynote Event in September. Phil Schiller, Apple's senior vice president, said. “ 【小题3】”.

But it's already been done. In a video posted on community website Reddit on Nov 3, two brothers showed how they were each able to unlock the same iPhone X using their own face. Quartz reported. And they aren't even twins.

“We may expect too much from bio-metrics.” Anil Jain, a computer science professor at Michigan State University. told CBS news. “No security systems are perfect.”

Earlier this year, Jain found a way to trick biometric security. Using a printed copy of a thumbprint, she was able to unlock a dead person's smartphone for police.

“It's good to see bio-metrics being used more,” Jain told CBS News, “because it adds another factor for security. 【小题4】.”