>I would not say it is "scanning" as the device doesn't know the final result (match or not) I don't think this is a relevant distinction. If the device had kn

>I would not say it is "scanning" as the device doesn't know the final result (match or not) I don't think this is a relevant distinction. If the device had known the result and just sent Y/N to Apple, what would change in your argument? Nothing. Your last sentence would be just as arguable. >Isn't this like "scanning in iCloud" but without Apple needing to have a decrypted photos in their servers? Note that Apple right now already has the decrypted photos since they have the decryption key. There's no evidence they are even considering E2EE right now, and since there are other legal requirements for scanning (e.g. terrorist material) I'm not sure this allows them to implement E2EE. And I don't see how the client-side feature can remain as is. There are obvious cases that would be caught by the typical server-side scanning and won't be caught here, so once the door was opened, the government will pressure. For example: * What happens when the NCMEC database updates? It could be that the phone rescans all your images. Or that apple keeps the hash and rescans that. Note that the second case is identical to some server-side scanning implementations. * What happens when you upload something to iCloud, delete it from your phone and then the NCMEC database updates? If Apple keeps the hash, it's just server-side again. If Apple doesn't keep it but uses client side scanning, the phone has to keep the hashes so you can't ever truely delete an image you've taken. If there's no rescan, the bad guys get to keep CSAM on iCloud so long as they passed the original scanning with the older NCMEC database - surely the government wouldn't accept that. (I considered scanning on download but I don't know if Apple/the government would like this compromise, since with that approach CSAM can remain on iCloud undetected so long as it's not downloaded, anyway it's not in the original papers). Basically, either they scan on client-side more than they let on or we end up in a world with both server-side and client-side scanning. The latter is arguably worst of both worlds, the former has implications which need to be looked at.