[zepto]

> Sorry, this is not even wrong.

Probably a mistake to say things like this, when the public documentation contradicts you.

> The visual derivative is not matched against anything, and there is no "original" visual derivative to match against.

Bullshit.

Here is the relevant paragraph from Apple’s documentation:

“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 possi- bility that the match threshold was exceeded due to non-CSAM images that were ad- versarially perturbed to cause false NeuralHash matches against the on-device en- crypted 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...