3 ms·

But wouldn't the homomorphic encryption prevent Apple's servers from knowing if there was a match or not?

NooneAtAll3 2y ago
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?
- Thorrez 2y ago
  >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.
amatecha 2y ago
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-encryption https://machinelearning.apple.com/research/homomorphic-encry..., during the period of generating
- fragmede 2y ago
  > 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://spiralwiki.com/ https://spiralwiki.com/ https://news.ycombinator.com/item?id=31668814 https://news.ycombinator.com/item?id=31668814
  - amatecha 2y ago
    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)
    - lloeki 2y ago
      > they really could have explained that better. The language used in Apple's article This one? https://machinelearning.apple.com/research/homomorphic-encryption https://machinelearning.apple.com/research/homomorphic-encry... I find that description perfectly clear for someone who doesn't already know what homomorphic encryption means: > One of the key technologies we use to do this is homomorphic encryption (HE), a form of cryptography that enables computation on encrypted data (see Figure 1). HE is designed so that a client device encrypts a query before sending it to a server, and the server operates on the encrypted query and generates an encrypted response, which the client then decrypts. The server does not decrypt the original request or even have access to the decryption key, so HE is designed to keep the client query private throughout the process. Later: > HE excels in settings where a client needs to look up information on a server while keeping the lookup computation encrypted. And there's more perfectly layman-understandable in PIR and PNSS sections, complete with real-life examples and simple diagrams. One just has to read the goddamn thing, which apparently is an insurmountably tall order these days for content that is more than 250 characters.
      - amatecha 2y ago
        I read that. It doesn't actually explain how the server can tell me the Eiffel Tower is in my photo without knowing it's telling me that. It glosses over the mechanism by which it can tell me what's in my photo without the service itself knowing. Yeah, cool, never-decrypted. So how do they match up? An ultra-abstract "A[encrypted] + B[encrypted] = A+B[encrypted]" doesn't tell me anything. As an aside, your unfounded derision about "RTFA" is unwarranted and unnecessary. That was an unusually-hostile response for like, just talking about things.

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?

Thorrez 2y ago
>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.

amatecha 2y ago

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-encryption https://machinelearning.apple.com/research/homomorphic-encry..., during the period of generating

fragmede 2y ago
> 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://spiralwiki.com/ https://spiralwiki.com/ https://news.ycombinator.com/item?id=31668814 https://news.ycombinator.com/item?id=31668814
- amatecha 2y ago
  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)
  - lloeki 2y ago
    > they really could have explained that better. The language used in Apple's article This one? https://machinelearning.apple.com/research/homomorphic-encryption https://machinelearning.apple.com/research/homomorphic-encry... I find that description perfectly clear for someone who doesn't already know what homomorphic encryption means: > One of the key technologies we use to do this is homomorphic encryption (HE), a form of cryptography that enables computation on encrypted data (see Figure 1). HE is designed so that a client device encrypts a query before sending it to a server, and the server operates on the encrypted query and generates an encrypted response, which the client then decrypts. The server does not decrypt the original request or even have access to the decryption key, so HE is designed to keep the client query private throughout the process. Later: > HE excels in settings where a client needs to look up information on a server while keeping the lookup computation encrypted. And there's more perfectly layman-understandable in PIR and PNSS sections, complete with real-life examples and simple diagrams. One just has to read the goddamn thing, which apparently is an insurmountably tall order these days for content that is more than 250 characters.
    - amatecha 2y ago
      I read that. It doesn't actually explain how the server can tell me the Eiffel Tower is in my photo without knowing it's telling me that. It glosses over the mechanism by which it can tell me what's in my photo without the service itself knowing. Yeah, cool, never-decrypted. So how do they match up? An ultra-abstract "A[encrypted] + B[encrypted] = A+B[encrypted]" doesn't tell me anything. As an aside, your unfounded derision about "RTFA" is unwarranted and unnecessary. That was an unusually-hostile response for like, just talking about things.