Apple’s device surveillance plan is a threat to user privacy

Re:Apple’s device surveillance plan is a threat to user priv... by kemayo on Wednesday August 18, 2021 @08:25PM (#28228938)

For your example, wouldn't that only work to make the original source image that's polluting the CSAM database look like CSAM in lowres? The actual document-image the oppressive government is looking for that'd trigger the match wouldn't have the CSAM included.

That said, I do think it'd be nice to have a better demonstration of exactly what this "derivative" the reviewers would be looking at is. There's a lot of variations there, balancing false-positive privacy concerns, the mental health of the reviewers, potential downsampling issues, etc.

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Re:Apple’s device surveillance plan is a threat to user priv... by simondotau on Wednesday August 18, 2021 @09:34PM (#28229352)

I agree, it would be useful if Apple could be clearer by what they mean by a derivative. I recall reading somewhere that it's a reduced resolution, grayscale copy of the image. I can't vouch for that, but that would be a plausible notion of what the "derivative" would be.

Personally I would also be placing a hard watermark in the middle of the image, or maybe some hard slashes randomly through the image, so that "clean" images cannot leak out of human review.

Let's imagine that the derivative is a 0.5 megapixel, grayscale, watermarked, HEIC-compressed copy of the original image. This would be plenty to determine with zero ambiguity that the image is actually "A1" classified, i.e. depicts a prepubescent minor ("A") engaged in a sex act ("1").

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