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Fully homomorphic encryption and the dawn of a private internet

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Re: Fully homomorphic encryption and the dawn of a private internet

#91

Post by Retr0id »

immibis wrote: post #68
Retr0id wrote: post #59

Earlier quoted context omitted.

I think SGX (et al) can still be useful as part of a layered defense. We know how to defeat security mitigations like NX and ASLR, but that doesn't mean they're useless. The problem is that SGX is marketed as the solution.

NX and ASLR make it harder for other people to exploit your code on your computer. SGX tries to make it easier for other people to run code on your computer without you seeing the code or what it's doing. They're not in the same category.

SGX on consumer client devices is sucky for that reason, but SGX on the server can be used to defend user interests.

If I put my sensitive customer data inside SGX (such that I can operate on it but not extract it), and the nation-state adversary says "we have a warrant for your customer data, hand it over", I can reasonably say "I can't".

I could also produce attestations that my code really is running inside SGX, verifiable by clients (this is a weak proof since it assumes SGX is not compromised, but it's better than nothing).

The adversary may demand physical access to the server pwn SGX themselves, but like bypassing ASLR or NX, that's an extra step. They're only going to bother if they really care about that data.

Re: Fully homomorphic encryption and the dawn of a private internet

#92

Post by xhrpost »

Tryk wrote: post #79
xhrpost wrote: post #72

Earlier quoted context omitted.

This made me wonder if there is such a thing as homomorphic compression. A cursory search says yes but seems like limited information.

What do you mean by homomorphic compression? Given that the operations you can execute on the ciphertext are Turing complete (it suffices to show that we can do addition and multiplication) then it follows that any conceivable computation can be performed on the ciphertext.

Oh this is outside the context of encryption. My curiosity was, is there such a compression function that permits operations on the compressed data without first decompressing it?

Re: Fully homomorphic encryption and the dawn of a private internet

#93

Post by thrance »

perlgeek wrote: post #63

FHE might allow arbitrary computation, but I use most services because they have some data I want to use: their search index, their knowledge, their database of chemicals, my bank account transactions, whatever. So unless Google lets me encrypt their entire search index, they can still see my query at the time it interacts with the index, or else they cannot fulfill it. The other point is incentives: outside of some…

Here's an implementation of a fully private search engine using FHE that allows querying Wikipedia with the server remaining oblivious as to what you're reading: https://spiralwiki.com/

Re: Fully homomorphic encryption and the dawn of a private internet

#94

Post by Barrin92 »

"The implications are big. The entire business model built on harvesting user data could become obsolete. Why send your plaintext when another service can compute on your ciphertext?"

Why do people always do this thing where they think inventing a technology has somehow changed economics? I think the implications are very small. There is value in people's user data and people are very eager to barter that value against cheaper services, we can tell because people continue to vote with their wallets and feet.

You could already encrypt or offer zero retention policies on large amounts of internet businesses and every major company has competitors that do, but they exist on the margins because most people don't take that deal.

Re: Fully homomorphic encryption and the dawn of a private internet

#95

Post by eynsham »

throwaway478484 wrote: post #85
NoImmatureAdHom wrote: post #80

Earlier quoted context omitted.

> The statements made in the linked description of this cannot be true, such as Google not being able to read what you sent them and not being able to read what they responded with. The beautiful thing is: they are :-)

If Google’s services can respond to queries, they must be able to read them. If A uses a cereal box cipher and B has a cereal box cipher, B can can make sense of encoded messages A sends them, A can ask about the weather, and B can reply with an encoded response that A can decode and read. B is able to read A’s decoded query, and B knew what the weather was, and responded to A with that information. Security is not m…

What do you think fully homomorphic encryption is, then?

Re: Fully homomorphic encryption and the dawn of a private internet

#96

Post by reactordev »

bawolff wrote: post #78
hoppp wrote: post #74

Earlier quoted context omitted.

Its like, python can be 400 times slower than C++, but people still use it.

Yeah, because people use python when it doesn't matter and c++ when it does (including implicitly by calling modules that are backed by c implementations). That is not an option with FHE. You have to go all in.

And people will use FHE where it matters and plaintext where it doesn’t…

Re: Fully homomorphic encryption and the dawn of a private internet

#97

Post by [deleted] »

swores wrote: post #71
perching_aix wrote: post #60

Earlier quoted context omitted.

Of course. My math only "checks out" if you accept and account for the additional assumption I made there: that the datapoints provided in the question have been rounded or were low resolution from the get-go. The motivation behind this assumption is twofold: the numbers in the question are awfully whole (atypical for any practical problem), and that just the rote derivation of it all doesn't produce very interesting…

Considering the first mile would need to have been faster than 23mph for your 41mph to give an average of 30... your answer is either completely wrong, or is "if we pretend that the numbers are completely different to what they are then my answer is right", either way it just seems pointlessly wrong rather than pretty fun. But I guess good for you if you enjoyed working out that answer.

[deleted]

Re: Fully homomorphic encryption and the dawn of a private internet

#98

Post by dachrillz »

xhrpost wrote: post #92
Tryk wrote: post #79

Earlier quoted context omitted.

What do you mean by homomorphic compression? Given that the operations you can execute on the ciphertext are Turing complete (it suffices to show that we can do addition and multiplication) then it follows that any conceivable computation can be performed on the ciphertext.

Oh this is outside the context of encryption. My curiosity was, is there such a compression function that permits operations on the compressed data without first decompressing it?

One that is kind of in this spirit is that you can describe sparse matrices by omitting all the zeros and only describe the indices that have data. In this compression you can still perform normal matrix operations without having to unpack them into the “normal form”. Now this is neither encryption nor a particularly interesting compression, but it does prove that it is possible in principle ;p

Re: Fully homomorphic encryption and the dawn of a private internet

#99

Post by johnisgood »

dismalpedigree wrote: post #89
kube-system wrote: post #23

Earlier quoted context omitted.

Sure, hardware is cheap. However if you actually follow the 3-2-1 rule with your backups, then you need to include a piece of real estate in your calculation as well, which ain’t cheap.

I have true 3-2-1 backups on a server running proxmox with 32 cores, 96gb of ram, and 5TB of ssd disks (2TB usable for VMs). Cost me $1500 for the new server hardware 2 years ago. Runs in my basement and uses ~30w of power on average (roughly $2.50/mo). The only cloud part is the encrypted backups at backblaze which cost about $15/mo. Its a huge savings over a cloud instance of comparable performance. The closest mat…

Only $1500? How much would this setup cost today?

Re: Fully homomorphic encryption and the dawn of a private internet

#100

Post by darkwater »

seanhunter wrote: post #28
txdv wrote: post #20

Earlier quoted context omitted.

I get that there is a big LLM hype, but is there really no other application for FHE? Like for example trading algorithms (not the high speed once) that you can host on random servers knowing your stuff will be safe or something similar?

I speak as someone who used to build trading algorithms (not the high speed ones) for a living for several years, so knows that world pretty well. I highly doubt anyone who does that will host their stuff on random servers even if you had something like FHE. Why? Because it's not just the code that is confidential. 1) if you are a registered broker dealer you will just incur a massive amount of additional regulatory…

But shouldn't proper FHE address most of these concerns? I mean, most of those extra measures are exactly because if you can physically access the server, it's game over. With FHE, if the code is trusted, even tampering with the hardware should not compromise the software.
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