Does Touch ID Decay Over Time? | Cult of Mac

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


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