According to the latest news, Apple confirmed its plan to deploy a new technology within iOS, macOS, watchOS, and iMessage in a briefing on Thursday afternoon. The new technology will detect potential child abuse imagery. This time, the company has clarified crucial details from the ongoing project.
Apple said for devices in the US, new versions of iOS and iPadOS rolling out this season will have a “new applications of cryptography to help limit the spread of CSAM [child sexual abuse material] online, while designing for user privacy.”
The project is elaborated on a new “Child Safety” page on Apple’s website. The most controversial implementation of this system is performing on-device scanning before an image is backed up in iCloud. It appears scanning does not occur till a file is getting backed up to iCloud. Apple receives data about a match if the cryptographic vouchers of a particular account meet a threshold of matching known CSAM.
For all these years, Apple has used hash systems to scan for child abuse imagery sent over email. Similar technology is used by Gmail and other cloud email providers.
The newly announced program will apply scans to user images stored in iCloud Photos even if the images are never shared. In a PDF provided along with the briefing, Apple specified “Apple does not learn anything about images that do not match the known CSAM database. Apple can’t access metadata or visual derivatives for matched CSAM images until a threshold of matches is exceeded for an iCloud Photos account. The risk of the system incorrectly flagging an account is extremely low.
In addition, Apple manually reviews all reports made to NCMEC to ensure reporting accuracy. Users can’t access or view the database of known CSAM images. Users can’t identify which images were flagged as CSAM by the system”.
Apple commissioned technical assessments of the system from three independent cryptographers (PDFs 1, 2, and 3) and confirmed the mathematical robustness of the codes. professor David Forsyth, chair of computer science at the University of Illinois said “In my judgment this system will likely significantly increase the likelihood that people who own or traffic in such pictures (harmful users) are found; this should help protect children. The accuracy of the matching system, combined with the threshold, makes it very unlikely that pictures that are not known CSAM pictures will be revealed.”