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Comment by jodrellblank | Hacker News Reader

> "Apple's CSAM would scan your offline photos."

No it wouldn't. It would only scan photos you upload to their cloud.

"This feature only impacts users who have chosen to use iCloud Photos to store their photos. It does not impact users who have not chosen to use iCloud Photos. There is no impact to any other on-device data."

and

"Does this mean Apple is going to scan all the photos stored on my iPhone? No. By design, this feature only applies to photos that the user chooses to upload to iCloud Photos, and even then Apple only learns about accounts that are storing collections of known CSAM images, and only the images that match to known CSAM. The system does not work for users who have iCloud Photos disabled. This feature does not work on your private iPhone photo library on the device."

- https://www.apple.com/child-safety/pdf/CSAM_Detection_Techni...

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You're right - I misremembered. Kinda wish HN would let me edit.

You are spreading misinformation. I don’t know if on purpose or ignorance.

https://www.cbsnews.com/news/child-sexual-abuse-scans-apple-...

They were very much planning to scan all photos on the device independent of iCloud. It was going to be another phase of the rollout. It was going to be in iOS 15.x and they backpedaled.

I think that's just imprecision on the part of noted tech news outlet CBS.

Apple clearly documented that this was only for iCloud uploaded photos, and indeed the technical description makes clear that this is only designed to work with uploaded photos: https://www.apple.com/child-safety/pdf/CSAM_Detection_Techni....

Apple clearly said they scan the photos on your phone not in your cloud account. They say it is designed to work with iCloud photos and they are processed / scanned on your photo before they are uploaded to the cloud.

Not sure why they would need to do that. It does open up your phone for scanning and uses beyond what they initially layout.

Yeah, I think this is what freaked everyone out, but it's pretty clear the intention of on-device scanning was that it would work even if they had client-side encryption of photos before upload .

The whole point of the protocol (as described in the Apple whitepaper) is to allow clients to attest to perceptual hash matches without the server having access to the plaintext.

So, the irony of all of this is that the Apple design is effectively more private than the status quo, but everyone freaks out about it.

I think the ostensible goal was privacy preservation for photos whose perceptual hashes don’t match (i.e. most photos), which would never need to be uploaded without end to end encryption. But I agree it puts them within striking distance of scanning fully offline photos, even if the initial implementation doesn’t.

I am spreading information from the people who designed and built it on purpose to counteract the clickbait sky-is-falling misinformation.

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