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Practical homomorphic encryption over integers (2017)

arxiv.org

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Re: Practical homomorphic encryption over integers (2017)

#31

Post by betterunix2 »

mcbits wrote: post #12
soberhoff wrote: post #11

Earlier quoted context omitted.

How does this affect internet searches?

Potentially a search engine could provide results without knowing the actual query, although that would make it difficult to identify new trends or determine which results are/aren't being clicked, so it probably wouldn't be competitive as a general purpose search engine.

It would also be completely impractical, since the search engine would necessarily have to perform some sort of scan of its entire database to respond to every query (otherwise it would, in fact, learn something about the query).

Re: Practical homomorphic encryption over integers (2017)

#32

Post by betterunix2 »

jldugger wrote: post #27
hossbeast wrote: post #26

Earlier quoted context omitted.

Does it generalize? Can you in theory perform any computation in this way?

To the extent that computations are feasible, yes. There was a pretty big paper like a decade ago proposing a fully homomorphic system. It was pretty much impractical, running like a million times slower than native instructions. I assume without reading that this post's paper reduces that multiplier to hundreds of thousands. edit: reading the abstract, it looks like they don't have a faster fully homomorphic system,…

Actually the paper presents nothing; their security proofs make no sense at all and the rest of the paper is not much better.

Re: Practical homomorphic encryption over integers (2017)

#33

Post by betterunix2 »

guiomie wrote: post #2

This is one of the current 'tech' trends that I'm following, the idea of homomorphic encryption is really cool. I feel like there is a lot of real world applications for it, but I have failed to find them yet.

The "textbook" application is spam filtering for encrypted mail.

Re: Practical homomorphic encryption over integers (2017)

#34

Post by betterunix2 »

tfha wrote: post #29
sp332 wrote: post #10

Earlier quoted context omitted.

Cloud computing is the big one. You might want to rent some remote computer time without sending plaintext data to a third party. Homomorphic encryption lets you upload encrypted data and instructions for a third party to operate on it without having to decrypt it first. Edit: Try Greg Egan's book Permutation City .

If we had proper homorphic encryption, we could use regular home user machines for a cloud, airbnb style. You can't do that today because the security risks are completely unmanageable. But that all changes with homomorphic encryption. Today it's not practical, but we see advances like this every year, maybe in a decade it will be practical.

You need more than FHE for that; just because I cannot see what I am computing does not mean I will compute the answer correctly. There are ways this can be resolved but it pushes practicality even further back.

Re: Practical homomorphic encryption over integers (2017)

#35

Post by hardbyte »

hossbeast wrote: post #26
bo1024 wrote: post #24

Earlier quoted context omitted.

You encrypt some data and send it to Bob. Bob does some computations on the encrypted data and sends you the (still-encrypted) results. You decrypt the results to get the answer of your computation. Bob never learns what your data is or what the results are. The term "homomorphic" roughly refers to the fact that the encrypt/decrypt functions go "outside" the computation. That is, if Bob is applying the function f, we…

Does it generalize? Can you in theory perform any computation in this way?

Even with partially homomorphic encryption and additional "privacy preserving protocols" you can carry out pretty general computation tasks such as machine learning. Have a look at this blog post using the Paillier cryptosystem for a federated linear regression - https://blog.n1analytics.com/distributed-machine-learning-an...

Re: Practical homomorphic encryption over integers (2017)

#36

Post by dlubarov »

betterunix2 wrote: post #34
tfha wrote: post #29

Earlier quoted context omitted.

If we had proper homorphic encryption, we could use regular home user machines for a cloud, airbnb style. You can't do that today because the security risks are completely unmanageable. But that all changes with homomorphic encryption. Today it's not practical, but we see advances like this every year, maybe in a decade it will be practical.

You need more than FHE for that; just because I cannot see what I am computing does not mean I will compute the answer correctly. There are ways this can be resolved but it pushes practicality even further back.

Not sure what you mean? Correct evaluation (modulo some negligible error) is part of the usual FHE definition.

Re: Practical homomorphic encryption over integers (2017)

#37

Post by JadeNB »

dlubarov wrote: post #36
betterunix2 wrote: post #34

Earlier quoted context omitted.

You need more than FHE for that; just because I cannot see what I am computing does not mean I will compute the answer correctly. There are ways this can be resolved but it pushes practicality even further back.

Not sure what you mean? Correct evaluation (modulo some negligible error) is part of the usual FHE definition.

Perhaps it’s referring to human malice rather than mathematical error: that we’d want some sort of certification that the operation performed off-site was actually the one requested?

Re: Practical homomorphic encryption over integers (2017)

#38

Post by tylersmith »

dlubarov wrote: post #36
betterunix2 wrote: post #34

Earlier quoted context omitted.

You need more than FHE for that; just because I cannot see what I am computing does not mean I will compute the answer correctly. There are ways this can be resolved but it pushes practicality even further back.

Not sure what you mean? Correct evaluation (modulo some negligible error) is part of the usual FHE definition.

You can't evaluate the correctness/trust the result without performing the computation yourself or receiving a proof of correctness, e.g. a SNARK.

Re: Practical homomorphic encryption over integers (2017)

#39

Post by technocratius »

jerf wrote: post #4
guiomie wrote: post #2

This is one of the current 'tech' trends that I'm following, the idea of homomorphic encryption is really cool. I feel like there is a lot of real world applications for it, but I have failed to find them yet.

I really want to sarcastically say "blockchain homomorphic encryption", but, well, it's not necessarily a terrible idea, honestly. One can imagine some combination of the primitives in which you could prove that you added here the same amount you subtracted from there, that neither total is below zero, but for which the number actually transferred is encrypted. The current use case for something like BitCoin is often…

You should look into Enigma (blockchain company). They use this type of technology to enable private decentralized multi-party computation.

Re: Practical homomorphic encryption over integers (2017)

#40

Post by chaboud »

betterunix2 wrote: post #34
tfha wrote: post #29

Earlier quoted context omitted.

If we had proper homorphic encryption, we could use regular home user machines for a cloud, airbnb style. You can't do that today because the security risks are completely unmanageable. But that all changes with homomorphic encryption. Today it's not practical, but we see advances like this every year, maybe in a decade it will be practical.

You need more than FHE for that; just because I cannot see what I am computing does not mean I will compute the answer correctly. There are ways this can be resolved but it pushes practicality even further back.

Is it not practical to just saddle the dataset and compute request with a canary payload that is easily computable by the requestor?

If one can spoof the canary payload effectively, one would have broken the FHE scheme, probabilistically, right?

Unless I'm thinking about this wrong, the FH part of FHE makes this a pretty solvable problem. Is this not already fundamental to any FHE scheme?

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