Does Touch ID Decay Over Time?



Photo: Apple

Although not a new technology by any means, fingerprint scanners have historically been hamstrung by issues that have caused their sensors to degrade relatively rapidly, no longer being able to correctly read a fingerprint after only a few months.

When Apple introduced Touch ID with the iPhone 5s, they claimed to have solved that problem. Protected by nigh-indestructible Sapphire Glass, the Touch ID sensor is supposed to be able to read the curves and contours of your fingerprints at a resolution of up to 500 pixels per inch. But could Touch ID be just as susceptible to degradation issues over time as previous biometrics solutions?

Over on his blog, well-known tech blogger Dr. Drang says that he has had to reset Apple’s Touch ID and teach it how to read his fingerprints all over again every month or so, or else it would stop working reliably.

Drang speculates that the issue might be one in which Touch ID is polluting its own data stream. When you first train Touch ID to read your fingerprints, it creates a 500ppi scan of your fingertip whorls. Drang believes that Touch ID may continue to update this mental picture of your prints with subsequent scans, which may actually corrupt the Touch ID data pool as a whole.

Drang points out this is not the first time a system has decayed because it was corrupting itself:

Google, the Oliver Twist of data, has had to adjust its Page Rank system because it had been gamed by link farms to give high rankings to shitty websites with weak, derivative content (but lots of ads). Even better, though, is the story of the Google Translate API, which was shut down a couple of years ago, because the indiscriminate use of it had reduced the quality of the corpus Google used to learn from.

So is Touch ID really decaying over time? Daring Fireball’s John Gruber thinks it’s a strong possibility.

What about you? Do you have to constantly re-train your iPhone 5s to read your fingerprints correctly? Let us know in the comments.

Source: Dr. Drang

  • Adrayven

    Nope.. works fine.. since I first set it up.. I did find my mom’s gets worse over time.. Guess what.. She uses hand lotion and it start to smudge on the home button.. she kept re-training it.. and not cleaning the button.. so as the smudges changed, it would error again.

    In the end, when I noticed this, I told her to clean the button, then train it.. if it starts erroring again, clean button.. AMAZING! I’ve not heard another complaint! ROFL!

    Sometimes people over-think these things.. Most times, news articles are just looking for sensational click bait.. The button is basically a scanner.. clean it on occasion, you might be surprised.

  • NoBlindSpots

    I had to do the same thing but as Adrayven said im going to try cleaning the button then re scanning my finger

  • keir_john

    Mine works perfectly and I haven’t had to retrain it at all. Sounds like more FUD to me.

  • SumatraFire

    I have to retrain mine every couple of days.

  • MWinNYC

    Mine degraded after 1 month. There are hundreds if not thousands complaining of the same issue in the Apple Forum. Touch ID is still in beta. I’ve disabled mine- too much of a hassle to keep re-scanning my print.

  • iRikal

    Not once since i got my phone…

  • AustinNewdick

    I have not had to reset mine since I got it in September.

  • aardman

    Gave up on TouchID because it stops reading my fingerprint after about 2-3 weeks. Has a hard time especially if the interval between using TouchID is longer. Maybe the fingerprint would change gradually (moisture, dryness, affecting skin opacity, who knows?) and if the last scan was too long ago, then the change is too much that the fingerprint won’t match TouchID’s fingerprint profile anymore. Just a conjecture.

    I’m guessing the people who’ve had no problems live in areas where the weather is more stable? I’m in the upper midwest where temps and humidity can vary widely.

  • JohnInDC

    I find this to be a chronic problem. TouchID works great at first but its success rate slowly falls over a matter of days until after about, oh, 10 or so days it works less than 25% of the time, whereupon it’s more trouble than it’s worth. Retraining with new prints returns the success rate to 90%+ but it quickly begins to degrade again. I’ve had to retrain my phone 6-7 times at least.

    I don’t use hand lotions or work on, e.g. autos such that my fingers are covered in grease or oils. I am careful to place the meaty part of my thumb (the part I scanned) onto the scanner, and to ensure that my finger is contacting the ring on all sides. Cleaning the scanner doesn’t help.

    I don’t know why this affects some users but not others, but it’s an actual problem.

  • craigunderhill

    Mine has been crap since day one. I’ve trained and trained, but nothing helps. I’ve cleaned the button, re-trained, cleaned my hands, etc… nothing works. It’s almost like it quits trying. If I turn off the screen, then try again, it usually works. It’s inconsistent. I was hoping 7.1 would bring improvements, but it hasn’t. Anyone that says it’s been working fine since day one should consider themselves lucky. I’m really happy for you. I wish I was in your club.

  • iOSinister

    I am glad to find out I am not the only one having this issue. I have tried everything from cleaning, washing my hands, making sure my hands are completely dry and clean, then retraining. It works GREAT at first but usually after a week or so it slowly starts to fail more and more until eventually it doesn’t read my fingerprints at all. To the people saying it’s just people over thinking don’t be so quick to judge. I have especially noticed an issue in the past two months which I didn’t give too much thought to until reading other comments. I guess the rapid temperature change could have an effect but who knows really. I’ll keep using it because it doesn’t take long to retrain and when it’s working it’s a great little time saver. I hope it’s just a software fix but who knows.

  • trex67

    Comments seem about 50/50, but I haven’t had a single problem from day one – it work every time, 20 to 50 times a day, with little to no delay. I have 4 prints saved, 3 of mine, plus one of my wife’s fingers for that day I lose both of my hands in a tragic gardening accident.

    Is everyone moving their finger around while they do the training? I don’t know why there would be a problem, but it does NOT effect everyone.

  • ScottCLandis

    Haven’t had any major problems. Occasionally the scanner doesn’t activate, but after unlocking the phone and putting it back to sleep, it works. And for those saying it’s weather related, I live in the Pacific Northwest where, since I got my 5S over two months ago, the tempature has ranged from 15 F to 70 F and it has been rainy and clear.

  • guygubi

    Tip: add the finger twice (as 2 fingers) and it will work 99% of the time

  • jeff_allender72

    Got my 5s on the morning it came out, no problems here. I want touch ID on my iPads now!

  • craigunderhill

    Tip: add the finger twice (as 2 fingers) and it will work 99% of the time

    I’ve done this from the start, but I can’t say it has helped the problem for me personally.

  • MeganBlok

    My Touch ID has been great since day one. I have my thumbs in twice as separate fingers. Never have any issues unless my hand is sweaty.