December 04, 2013
When the iPhone 5S debuted, it came with the announcement of Touch ID, a technology aimed at making securing iPhones from unauthorized users easier. Instead of an iPhone requiring a passcode, the iPhone’s Touch ID sensor could read a fingerprint once the home button was pressed. If the fingerprint was previously stored as belonging to an approved user, the iPhone would unlock.
I was skeptical about how well Touch ID would work, but I’ve since become used to it. It’s definitely faster than swiping and entering a passcode, though the fingerprint sensing isn’t immediate - the lag time is noticeable. Thinking about this some more, it’s not just the lag that’s annoying, but it’s the momentary concern the fingerprint will be rejected.[^1]
Two days ago, Dr. Drang posted about the possibility that stored Touch ID fingerprints degrade, thus negatively affecting future accuracy of the Touch ID scanner. Apparently, Dr. Drang is not alone, and John Gruber has heard from readers that similar issues are being noticed.
After my iPhone 5 was set up for the first time, I set up Touch ID and things worked great until about a week and a half ago. Suddenly, Touch ID stopped recognizing my right thumb completely, though it recognized my other fingers just fine. My thumb wasn’t injured, dirty, or otherwise noticeably altered, so I just went ahead and reprogrammed Touch ID. As soon as I did, things worked perfectly again. A day or two later, I started getting false negatives, and would occasionally have to re-enter my passcode because Touch ID locked itself out.
Things seem a bit better now, but I’m still getting the occasional false positive, whereas I wasn’t getting any before. It’s become a bit annoying, but trying another finger after two negatives in a row is still faster than typing out my passcode. Still, I can’t help but think something’s up with how Touch ID works.
[^1] I’d prefer some sort of visual indicator my fingerprint was being “analyzed” for a match.