> If you look at how Apple detects contraband imagery, they hash every image that gets uploaded into the photos app. Those hashes are transmitted to servers that compare them to hashes of known contraband.

You're spelling out a specific process in detail--which is the only reason I'm picking on details. Do you have anything documenting what you're describing?

From what I remember, Apple's system was proposed, but never shipped. They proposed hashing your photos locally and comparing them to a local database of known CSAM images. Only when there was was a match, they would transmit the photos for manual confirmation. This describes Apple's proposal [1].

I believe what did ship is an algorithm to detect novel nude imagery and gives some sort of warning for kids sending or receiving that data. None of that involves checks against Apple's server.

I do think other existing photo services will scan only photos you've uploaded to their cloud.

I'm happy to make corrections. To my knowledge, what you're describing hasn't been done so far.

[1] https://www.hackerfactor.com/blog/index.php?/archives/929-On...

Aah okay - I remember it being proposed, but perhaps I wrongly assumed it had shipped. I do wonder sometimes if Apple is doing anything that we aren't privy to with photos that end up in iCloud.