App Turns Smart Phone into Key

Today lots of office doors open with smartcards, not keys.

Just wave your ID, and "open sesame."

Now you can do that with some smartphones, using an app called ShareKey.

It's based on Near Field Communication, or NFC—a way to send data wirelessly over short distances.

Many Android phones already have NFC chips built in.

Here's how ShareKey works.

After installing the app, you register with a central server.

In a hotel, that would be run by the front desk.

They'd verify your smart phone as an authorized guest, and send you an encrypted key—valid only for the length of your stay.

Then, wave your phone over your room's lock.

In just half a second, the lock verifies the key's authenticity and that the key is stored on your phone, not a thief's.

Want to let a friend in?

Ask the app to issue a new key linked to your friend's phone—and just text or e-mail it.

The researchers are presenting ShareKey in March at the CeBIT trade fair in Germany.

Researchers say ShareKey could be used for offices, homes or Zipcar.

Just make sure to keep your phone under lock and key.

本文节选自《60-Second Science American》