It's a cool idea: certain approaches to encryption still allow math to be performed. Here's one example: say you encrypt data X with algorithm Z. then you could multiply Z by four, which would also multiply X by four. So you can run computations on the encrypted data without decrypting it.

It would be quite complex, but I suppose you could run a machine learning model this way to tag images without ever seeing the image, or knowing the resulting tag. Only the decryption key can be used read the results (which is on the user's iphone, I suppose).

However... I don't know how much compute cost this adds to an already expensive computation. The encryption used might not be the strongest out there. But the idea is pretty cool!

Never accept the technology just because it is optional. Eventually it will become default and eventually maditory.

I have an iPad, now I am scared.. Should I do something about this?

Ease of use vs all the rest, as usual

"does this even if you’ve already opted out of uploading your photos to iCloud." damn that's a bit much!

Edit; in this thread, people who miss the point of homomorphic encryption to dunk (sadly often rightfully so) on Apple.