Apple unveiled plans to scan U.S. iPhones for images of child sexual abuse, drawing applause from child protection groups but raising concern among some security researchers that the system could be misused, including by governments looking to surveil their citizens.
The tool designed to detected known images of child sexual abuse, called “NeuralHash,” will scan images before they are uploaded to iCloud. If it finds a match, the image will be reviewed by a human. If child pornography is confirmed, the user’s account will be disabled and the National Center for Missing and Exploited Children notified.
Separately, Apple plans to scan users’ encrypted messages for sexually explicit content as a child safety measure, which also alarmed privacy advocates.
The detection system will only flag images that are already in the center’s database of known child pornography. Parents snapping innocent photos of a child in the bath presumably need not worry. But researchers say the matching tool — which doesn’t “see” such images, just mathematical “fingerprints” that represent them — could be put to more nefarious purposes.
Matthew Green, a top cryptography researcher at Johns Hopkins University, warned that the system could be used to frame innocent people by sending them seemingly innocuous images designed to trigger matches for child pornography. That could fool Apple’s algorithm and alert law enforcement. “Researchers have been able to do this pretty easily,” he said of the ability to trick such systems.