By now, you’ve probably heard: The new iPhone X doesn’t have a home button, and it doesn’t have a fingerprint sensor either.

How will you log into your phone? How will you tap-to-pay? Apple’s hoping you’ll use the brand-new Face ID — where you simply look at your phone to be logged in automatically. 

In the wake of news that Samsung’s rival Face Unlock feature isn’t particularly secure, you might be wondering whether that’s really a great idea. The good news: Apple uses a rather different, more-or-less proven technology.

On Tuesday, Apple made a big deal about the iPhone X’s new TrueDepth sensor, which crams a ton of hardware into a pretty tiny space — the typical front-facing camera, microphone, speaker, ambient light and proximity sensors are now joined by a new infrared camera, dot projector and flood illuminator.

But while that sounds awfully complicated, the process appears to be pretty simple: The phone lights up your face, fires out 30,000 invisible infrared dots that highlights your features and creates a rough pattern, takes pictures of those dots with the infrared camera, and decide whether the picture looks like you. 

Apple says the chance of fooling Face ID is literally 1 in a million — compared to 1 in 50,000 that a random person could use their fingerprint to unlock an older iPhone. 

If the tech sounds familiar, you might have used a similar technology before: Microsoft’s Kinect, for the Xbox 360 and Xbox One, allowed you to control games by watching the pattern of infrared dots that it projected across your living room. 

The reason it works better than Samsung’s Face Unlock? These so-called depth cameras can basically see in 3D, so they aren’t fooled by flat photos.

In fact, Apple isn’t the first company to let you log into a computer using the same basic idea. Microsoft’s Windows Hello will let you log into Windows 10 computers if they’re equipped with a depth-sensing infrared camera setup, and can allegedly even tell twins apart. I’ve reviewed a few laptops with the feature, and it’s pretty cool. 

Still, Apple definitely seems to be breaking some new ground with Face ID — both in terms of fitting the tech into a reasonably thin, narrow phone and by getting banks on board. Apple says Face ID is secure enough you can use it to pay in actual brick-and-mortar stores — something we were led to believe would take years to become a reality. 

Apps that used the Touch ID fingerprint sensor — Apple namedropped Mint, 1Password and E-Trade — should be able to use Face ID as well.

To make Face ID that secure, private and still speedy enough to use quickly, Apple says it never stores your face scans in the cloud, but rather on an encrypted part of your phone. 

Specifically, it runs every facial scan through the Secure Enclave, a dedicated co-processor with its own encrypted memory, secure boot process and a random number generator. Plus, the tech is designed to only recognize you when you’ve got both eyes open and are looking straight at the phone.

Just know that a glance isn’t particularly secure if, say, an authoritarian government asks you to unlock your phone.

On a less somber note, Apple says it uses machine learning so Face ID can grow with you, and is smart enough to still recognize your face if you change hairstyles, add a scarf and hat, or grow a beard. (Obviously, we haven’t had time to test that yet.)

So no, it’s not quite a new idea. But perhaps Apple has all the pieces of the puzzle to make glanceable payments a ubiquitous reality at last.

Apple Sept. 12 iPhone event live coverage: Read what happened in CNET’s live blog.

iPhone X, iPhone 8: Everything we know about Apple’s new iPhones.

Everything Apple just announced: Get the details.