We keep hearing rumors that Apple's next iPhone, expected to be announced Sept. 10, will have a fingerprint sensor. The rumors say it will be a convex home button covered with super-hard sapphire crystal. The presence of related code found by developers in iOS 7 support these rumors. So assuming all this is true, what's the point? Security, of course. A helpful post on Macworld explains that passwords are fairly weak security, especially since so many people still do dumb things like use "password" as their password. Even two-factor authentication, in which a code is sent via SMS, still doesn't guarantee that the person with phone in hand is the rightful owner.
The ideal, they say, is biometric identification, which looks at some unique facet of you to determine that you indeed should have access. Apple's sensor will scan your fingerprint, translate it into a digital signature, probably encrypt it, and then upload it to their servers. An actual image of your fingerprint doesn't get uploaded, so you don't need to worry about thieves intercepting it.
The Macworld posting says not only will this make the data on your iPhone more secure, but it will also reduce theft. If thieves find they're unable to access the phones they've stolen, they'll be less likely to steal them.
Ideally, Apple will make this level of security available to app developers. If you use your mobile device for online banking, it would create greater security if, in addition to entering a password and other security measures, access to your account also is contingent on biometrics.
Plus, I suspect there are many people like me who haven't enabled password control on their device. I simply hate the bother of some kind of extra step to access my device. So I'd really appreciate a home button that lets only me turn on the device. There's no added step: I'm simply pressing the home button as I usually do.
If you want to learn more about the fingerprint sensor we'll likely see in the iPhone, check out a post on 9To5Mac, as well as the in-depth article they reference that goes into detail about this technology.