Yahoo has unveiled a new system that can use ear and knuckle patterns to authenticate users, according to a PCWorld article.

"Unlocking your smartphone is something you do 150 times per day,” said Christian Holz, a research scientist at Yahoo Labs in Sunnyvale, California. “You want to make unlocking it convenient but also secure. That’s why fingerprint scanners are so successful.”

Using other body parts can be traced back to the pioneering French biometrics researcher Alphonse Bertillon, who focused on classifying ear structures, Holz added. “We’re basically exploiting that on commodity devices.”

Multiple users can have their ear prints or prints of other structures stored in a phone. The scans can also be used to lock documents in the device, so that an ear print or palm print from two or more users is needed to unlock it.