One of the big talking points of Apple’s new iPhone 5S is its Touch ID fingerprint sensor. It sounds great, but if you’re still not sure what it can do, how it works or how secure it is read on to find out.
How does it work?
The Touch ID fingerprint sensor is built right into the home button on the iPhone 5S. If you want to use the sensor then just place your finger lightly on the button. There’s no need to actually press it as a new stainless steel detection ring which surrounds the button will be able to detect your finger automatically.
The sensor itself uses laser cut sapphire crystal alongside a capacitive touch sensor to create an image of your fingerprint. If you want to get more technical about it, the sensor compares two layers of skin- your dermis, which is the top layer, is non conductive and is where your fingerprint is found, with your sub-dermis which is just below it and is conductive. By measuring the differences in conductivity between those two layers of skin it is able to build an accurate image of your fingerprint.
What use is it?
The most obvious application for Apple’s fingerprint sensor is to unlock your phone. In theory it should be a lot quicker and easier than using a pin or a password as you simply place your finger on the home button for a second or two. It’s designed to work from multiple angles too, so with any luck you shouldn’t get too many failed readings.
Beyond that it can also be used to authenticate purchases from iTunes, again saving you the effort of using a password. Theoretically in the long run it could all but replace passwords on your phone, allowing you to login to your email, bank and other accounts all with just a fingerprint, but none of those things are possible just yet.
Is it secure?
The short answer is yes, but with quite a few caveats. First of all it’s more secure than a lot of fingerprint scanners as many simply take a photo of your fingerprint, which could potentially be fooled by a photocopy or become unreliable once the sensor gets smudged. By actually measuring the capacitance of your finger Touch ID avoids those pitfalls. According to Apple the fingerprint is also only stored locally on your device and is presumably encrypted, meaning that hackers and even the NSA would probably have a hard time getting hold of it.
On the other hand, unlike a password your fingerprint can’t be changed, so if someone does ever get hold of it it’s no longer secure.
The bigger issue though is that it’s never likely to totally replace passwords, as worries that it might stop working or that your finger might get cut and therefore no longer be recognised means that there is always likely to be a password or pin alternative. The net result being that anyone who wants to access your phone has two ways they can go about it- either a pin/password or a fingerprint. For that reason it’s ultimately less secure than a password, but for most people it should still be plenty secure enough.
By Simon Thomas on 12th September, 2013