Comment by Thorrez
1 month ago
But wouldn't the homomorphic encryption prevent Apple's servers from knowing if there was a match or not?
1 month ago
But wouldn't the homomorphic encryption prevent Apple's servers from knowing if there was a match or not?
The server must know what it's matching at some point, to be able to generate a response:
> The server identifies the relevant shard based on the index in the client query and uses HE to compute the embedding similarity in this encrypted space. The encrypted scores and set of corresponding metadata (such as landmark names) for candidate landmarks are then returned to the client.
Even with the server supposedly not knowing the identity of the client, the response could simply include extra metadata like some flag that then triggers an instant send of that photo to Apple's (or law enforcement's) servers unencrypted. Who knows?
[0] https://machinelearning.apple.com/research/homomorphic-encry..., during the period of generating
> The server must know what it's matching at some point, to be able to generate a response
The entire point of homomorphic encryption is that it doesn't.
The homomorphic encrypted Wikipedia lookup example is pretty neat.
https://news.ycombinator.com/item?id=31668814
The setup for “that wasn’t real homomorphic encryption!” is in, when in 2-4 years it comes out that they were doing this exact thing.
The entire concept of a homomorphic encryption system is a land mine outside of obscure academic discussions. In practice systems marketed to the public as “homomorphic encryption” will result in user data exfil mark my words.
Oh, if that's the case, they really could have explained that better. The language used in Apple's article doesn't explain that the server cannot know the query or result (it implies as such, but doesn't make this clear, nor explain how/why)
4 replies →
(btw thanks for the links!) :)
not if you need to access from multiple devices (otherwise, what's the point of this feature?)
in that case it's the source of common key of "the same account" becomes the threat
and now you have to trust... megacorporation with closed-garden ecosystem... to not access its own servers in your place?
>not if you need to access from multiple devices (otherwise, what's the point of this feature?)
I don't think the feature works perfectly fine on single device. You take a ton of pictures on your iPhone. You search your photos for "Eiffel tower" and it shows you the photos you took of the Eiffel tower. I don't see why you need multiple devices.