Researchers fool smartphone fingerprint sensors using inkjet printer

Researchers at Michigan State University have found a way to unlock a smartphone protected by a fingerprint, by using an inkjet printer. The researchers, Kai Cao and Anil K. Jain, used a special conductive ink and paper made by a company called AgIC. They also noted that the fingerprint of the user has to be scanned at a resolution of 300dpi or higher. Before printing, though, the image of the scanned fingerprint needs to be reversed.

The researchers used Samsung Galaxy S6 and Huawei Honor 7 smartphones for testing, and managed to unlock both of them by using this technique. Although, Cao and Jain have noted in their paper, that the Honor 7 was slightly more difficult to hack than the Galaxy S6. The two researchers say that this technique is faster than the earlier method of creating a fingerprint ‘spoof’. The earlier method required the use of latex milk or wood glue. The quality of this spoof depended on the experience of the hacker, and the fingerprint itself took about 20 to 30 minutes to dry.