|
|
|
|
|
|
by JimDabell
1754 days ago
|
|
|
> Apple is not using PhotoDNA's hashes. Do you have a source for this, or is it an assumption you are making? > Apple is using a different system called NeuralHash. No, one of the systems Apple is using is NeuralHash. They also use a second, undisclosed system on the visual derivative before human review. While it’s possible they have invented two separate perceptual hashing systems, it’s also quite possible that they would use PhotoDNA for this. Details from Apple: > Once Apple's iCloud Photos servers decrypt a set of positive match vouchers for an account that exceeded the match threshold, the visual derivatives of the positively matching images are referred for review by Apple. First, as an additional safeguard, the visual derivatives themselves are matched to the known CSAM database by a second, independent perceptual hash. This independent hash is chosen to reject the unlikely possibility that the match threshold was exceeded due to non-CSAM images that were adversarially perturbed to cause false NeuralHash matches against the on-device encrypted CSAM database. If the CSAM finding is confirmed by this independent hash, the visual derivatives are provided to Apple human reviewers for final confirmation. — https://www.apple.com/child-safety/pdf/Security_Threat_Model... |
|
|
Yep I probably didn't phrase my question well enough but that was exactly part of what I was wondering.
They claim it's a second independent hash as you pointed out, so I would assume this is PhotoDNA server side, unless they made two separate hash systems (one which was not initially disclosed, if not implemented, at announcement time) ?
I'm also wondering exactly how they trained their NeuralHash, but may have missed some parts of the discussion. Supposedly NCMEC is not sharing the database of the "original" content that one would use to train such a system.
Edit : Guess that's a moot point now, they postponed it!