Galaxy Note 20

Note 20: screen protectors deceive the fingerprint reader admits Samsung

A surprising Galaxy Note 20 bug has just been recognized by Samsung: the smartphone’s fingerprint reader can be tricked with a simple screen protector. A recurring bug that had already been observed on the Galaxy S10 / Note 10.

Galaxy note 20
Credit: Unsplash

In general, when we make a mistake, we try everything not to repeat it. And that’s exactly what big manufacturers like Samsung do in general, as we could see for example with the Note 7 battery scandal – the same problem was never seen on a later model.

Yet it seems that the issues of biometrics and security remain in the background for the Korean manufacturer. In the release notes of its January 2021 security bulletin the manufacturer recognizes in fact an “abnormal behavior” of the fingerprint reader under the Note 20 screen. Problem that the January patch is therefore supposed to correct.

Samsung recognizes a new fingerprint reader problem on the Note 20

Apparently, sticking on a screen protector with the fingerprint of the smartphone owner was all it took to unlock a device protected by the Note 20’s ultrasonic sensor. This type of bug with potentially serious security implications is recurring on high-end Samsung smartphones.

It had indeed also been noted by some owners of Galaxy S10 and Note 10. If you have the Note 20, we therefore recommend that you go back to code authentication. if you want to wait before installing the update. We obviously invite Note 20 owners to test if possible the behavior of the smartphone with the screen protectors on which there are fingerprints before and after the update.

It also remains to be seen when Samsung will launch a high-end smartphone offering more truly secure biometric options – with why not an equivalent of the Face ID system on iPhone which would make it possible to secure the device via new methods of facial recognition.