Samsung Galaxy flagship fingerprint sensors are reported hackable using cheap screen protectors
A British woman has made headlines by claiming that her husband was able to unlock her Galaxy S10, even though his print was not registerd on the phone. This user has also reported that she was able to use her own non-registered prints to do the same. This may come as a shock for some, as Samsung integrates an ultrasonic fingerprint sensor into these devices rather than an optical one as in many other Android flagships.
The former is commonly regarded as generally superior in terms of robustness against hacking. Yet, the British user asserted that it did fail in her case. This was found to be due to the cheap silicone gel protector she had installed over the screen. This, apparently, is what caused the Galaxy S10's sensor to recognize non-authenticated prints.
Samsung has responded by issuing a statement on the matter. The OEM explained the phenomenon as a recognition of "3-dimensional patterns appearing on certain silicone screen protecting cases as users’ fingerprints". Therefore, this issue would also affect the Galaxy S10e, S10+, S10 5G, Note 10 and Note 10+.
Samsung has also stated that it will release a patch to prevent its recurrence in the future, which will be available next week at the soonest. In the meantime, the OEM advises users not to use such cases, and to delete all prints registered in the course of their use and re-register them with this accessory removed.
However, it already has exerted a negative effect on other users: the Kakao Bank in Korea has already contacted its customers with Galaxy S10- or Note 10-line devices intructing them to turn fingerprint authentication off.