Selfies are the new signatures at Amazon’s virtual checkout counter. The e-commerce giant has filed a patent application describing an app that lets users upload a photo or video of themselves for authentication — a process that’s supposed to be safer than simply tapping in your password. Which it will be, because the app has 16 crazy-specific ways of making sure you are actually you and not a high-quality facsimile of your fine self.

The application itself is more than 11,000 words, so in the interest of time, we’ve pulled out a few of the more interesting parts of this request for a patent.

1. It knows you’re alive.

2. It might ask you to blink to confirm you’re a real person.

3. Or wink.

Because this won't be awkward to do in public at all.

4. But it probably won’t ask you to hold your hand up over your face.

Motion detection will be necessary for selfie authentication because it’s pretty easy to trick a camera with a still, two-dimensional photo. But movements can be faked too — it’s not that hard to wave a hand in front of a photo, for example — so choosing the right types of actions is necessary.

5. It might use your phone’s infrared blasters to track the contour of your head.

6. It might also use infrared to check that your eyes are real.

The human eye is known to reflect infrared radiation differently than the rest of the face, providing crucial information about where your eyes are — or whether you have them at all.

7. Really, infrared sensing can be used to track how real your face is in general.

8. It might also use thermal imaging to do the same thing.

Your face, unlike paper, is pretty hot. 

9. The app knows how often you should be blinking.

The average person blinks once every 25 to 30 seconds. And each of those blinks should be no more than a second long. A video of a still photograph isn’t going to get past this thing.

10. It’s also pretty impatient.

If the app asks you to, say, gape your mouth, you better do it within five seconds of prompting, lest it mistake you for an intruder trying to screen prerecorded videos in front of the camera.

11. It might ask you to gape your mouth.

12. Or command you to frown.

13. It can blacklist (or whitelist) your IP address.

Because logging into Amazon multiple times from your home IP address is less sketchy than signing in from, say, the Taco Bell bathroom in Pacifica, CA.

14. It won’t just be used for e-commerce.

The e-commerce setting, the patent application points out, is merely an example. We could soon be using selfies to view financial information, stream music, or access saved video game info, too.

15. It isn’t restricted to smart phones.

While our phones are our selfie-grabbing device of choice, Amazon predicts we’ll be using e-book readers, tablets, notebook computers, personal data assistants, video gaming consoles or controllers, and portable media players to sign in too.

16. It’s supposed to be fun.

Like, really fun.
Photos via A 2D photograph, unlike your 3D face, reflects infrared light in a flat grid.