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Detecting child abuse pictures is not incompatible with end-to-end encryption if the detection is done locally. Facebook (or other messenger app owners) could
by jknz 7y ago
Detecting child abuse pictures is not incompatible with end-to-end encryption if the detection is done locally.
Facebook (or other messenger app owners) could train a good classification model to detect child abuse pictures on large servers and provide the model to smartphones locally. Before sending pictures, the app would run the trained model (which is cheap computationally). If if detects pictures of abuse with a certain accuracy, the app would block the transmission of the picture (possibly, explaining why to the user). If the detection of pictures of abuse happens again, the user could be banned from the app for 1 day, and if it happens more often the ban would become longer and longer.
That way facebook can fight child abuse without ever having the pictures.
- jpadkins 7y agodon't trust the client. How easy it would be for a motivated community to create a binary patch that skipped the local abuse checks?
- ijpoijpoihpiuoh 7y agoIf we're positing users clever enough to modify the client, then such users could also just modify the client to scramble all CP images so that they would not be detectable via fingerprinting and can only be descrambled by a patched client. People sending CP through whatsapp/FBM are not clever. If they were clever, they wouldn't be doing that. The justice department is not primarily interested in catching clever criminals, at least not via this particular mechanism.
- jknz 7y agoThere are ways to run trusted code on a client using remote enclaves (provided it is supported by the local CPU) https://signal.org/blog/private-contact-discovery/ https://signal.org/blog/private-contact-discovery/
- jandrese 7y agoHow are you going to get a pedo to setup a secure enclave on his box that you control? This is one of those technologies that are cool in theory but almost impossible to implement in practice on current hardware.
- abraae 7y agoWhy bother. Motivated community will just use their own encrypted tech to communicate.
- ENOTTY 7y agoModel inversion techniques may enable pedos to reconstruct the child abuse pictures from the model itself. This may be addressable through the secure enclaves you mentioned in another comment. I want to applaud you for thinking outside the box though.