Smartphones have taken larger and larger roles in our lives. As we dump our most important information — texts, emails, social media accounts, financial information, etc. into them — they’ve become a bigger target for criminals looking for an easy snatch and law enforcement trying to crack a case. There’s the now-infamous San Bernadino case, which the FBI believed held key information which
could help them understand and prevent future mass shootings, but there are in addition
countless smaller instances where investigators have begun pushing boundaries on what they can and cannot do.
Last month police solicited the help of Anil Jain, a computer science professor at Michigan State University. Jain works in biometric authentication and specializes in making them as secure as possible. These officers wanted him to do something a bit unusual, though. In an interview with Fusion.net, Jain and his student, Sunpreet Arora, went over the basic request.
There was a murder and the police thought there might be some clues on the victim’s phone, but it was locked with a fingerprint scanner. The police had prints on file (the victim had been arrested previously) and wanted to use a 3D printer to recreate the victim’s fingers. If you understand
how modern smartphones work, however, you understand
’s not quite adequate
Older touch sensors use what’s called a resistance touch screen. It simply detects pressure applied to it and registers a touch there. Capacitive screens, however, are far more complicated, and they’re the kind most commonly found in phones. They use human skin, or something with the same electrical properties as skin, to complete a circuit. Then, the phone uses changes in the electrical field caused by the presence of a finger to isolate the touch.
While it’s come a long way, 3D printing fake fingers isn’t quite adequate
. To make the fingers usable, investigators had to coat the models with metallic microparticles which
would in addition
work to complete the phone’s circuit and allow the model to be read.
As of right now, the models are being tested, and they may not work, but the (arguably gruesome) tech to do so isn’t far off. And it’s the latest in a series of phone privacy cases which
are pushing the limits of what we allow our society to do in the name of justice.
The fact which
the fingers are of the victim and not the suspect however, means which
there’s no chance which
they’d be delivering
a criminal case against the man — regardless of what’s found on his phone. But it does beg the question — does the right to privacy end when we die?