4 ms·

What is the actual value proposition of HE? The purpose of encryption is to hide information, if you are able to to do any meaningful comparison between two enc

What is the actual value proposition of HE? The purpose of encryption is to hide information, if you are able to to do any meaningful comparison between two encrypted records, you have an information leak, and encryption has failed.

AaronFriel 4y ago
The value proposition is that the hosting provider running your computation does not know what was computed.
sillysaurusx 4y ago
Imagine running an inference on a model in the cloud. Usually the cloud will have access to your model. That poses a problem if your model is highly sensitive. (Imagine the NSA wanting to run a model on North Korean servers. NK would immediately snatch up that model.) With FHE, you can theoretically avoid that. Someone can upload an encrypted model to the cloud. The cloud can do some computation on it (inference) and deliver an encrypted result. Then you can decrypt the result in the comfort of your own government^Whome. Obviously this is a bit of a stupid example, but just think of all the scenarios right now where you'd want to offload your computation on someone else, but you don't want to let them see the computation.
pmarreck 4y ago
There is no information leak, because the information is never decrypted. The encrypted operations are performed directly on the encrypted data and the still-encrypted result is returned to the client, to be decrypted at their convenience to view the result. That is the magic of FHE. Two identical cleartext values would likely not encrypt to the same ciphertext value (for example, you could get around that easily on the client end by simply incrementing any duplicate value by 1 before sending and then decrementing it by 1 again on return, assuming that is done undoably given the other operations happening); any comparison operation would also likely be encrypted and thus unknown to the server; so the server couldn't just linearly compare any two encrypted values to make deductions.

AaronFriel 4y ago

The value proposition is that the hosting provider running your computation does not know what was computed.

sillysaurusx 4y ago

Imagine running an inference on a model in the cloud. Usually the cloud will have access to your model. That poses a problem if your model is highly sensitive. (Imagine the NSA wanting to run a model on North Korean servers. NK would immediately snatch up that model.) With FHE, you can theoretically avoid that. Someone can upload an encrypted model to the cloud. The cloud can do some computation on it (inference) and deliver an encrypted result. Then you can decrypt the result in the comfort of your own government^Whome. Obviously this is a bit of a stupid example, but just think of all the scenarios right now where you'd want to offload your computation on someone else, but you don't want to let them see the computation.

pmarreck 4y ago

There is no information leak, because the information is never decrypted. The encrypted operations are performed directly on the encrypted data and the still-encrypted result is returned to the client, to be decrypted at their convenience to view the result. That is the magic of FHE. Two identical cleartext values would likely not encrypt to the same ciphertext value (for example, you could get around that easily on the client end by simply incrementing any duplicate value by 1 before sending and then decrementing it by 1 again on return, assuming that is done undoably given the other operations happening); any comparison operation would also likely be encrypted and thus unknown to the server; so the server couldn't just linearly compare any two encrypted values to make deductions.