Private AI is perfectly practical already and it really doesn't need Google at all. Besides the word 'practical' here is really stretching things.
Google is making private AI practical with homomorphic encryption
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Re: Google is making private AI practical with homomorphic encryption
#242So much inefficiency just to run it on someone else's untrusted hardware. Private AI is already possible today with local open-weight models running on hardware you control. Homomorphic encryption is cool technology, but I'm really not sure what problem it solves.
Re: Google is making private AI practical with homomorphic encryption
#243Earlier quoted context omitted.
To throw out some real and up-to-date numbers from [1] for FHE at "128-bit security level", to sort 8x 8-bit unsigned integers on the most ordinary of desktop PCs, wait 3 seconds for the result. Want to sort 32x 8-bit unsigned integers instead? Come back 34 seconds later for the result. update: also see [2] for some primitive unsigned 64-bit integer operation benchmarks with the TFHE-rs library (winner in the sorting…
It’s slightly better for LLMs because FHE is really bad at branches (it ends up essentially having to try both branches), making sorts nearly the worst possible thing to try since it’s all branches. In the case of AI most things are just addition and multiplication which can make some things faster since there aren’t as many branches. But we’re still nowhere near viability.
Re: Google is making private AI practical with homomorphic encryption
#244"hotword" detection, is this basically sniffing encrypted data for words the authorities don't want you to speak? Seems counterproductive to their stated aim of privacy.
Not even just by the authorities. This sounds like the wet dream of Google itself or any other data mining companies. You can just ship the most sensitive data around and extract signals to your hearts content - and even if it would be protected by law, you're good because hey, it's always encrypted, and the signals, ad assignments and profile markers are encrypted too! This is what I don't like about all this "I'm n…
Re: Google is making private AI practical with homomorphic encryption
#245Encryption or not, if it's on somebody else's server, it isn't yours. I don't believe Google has my best interest.
Besides, FHE is not always about using somebody else's server. At Belfort, in addition to FHE acceleration, we also explore such uses cases; https://belfortlabs.com/blog/encrypted-fraud-detection-with-... https://belfortlabs.com/blog/belfort-partners-with-lg-on-enc...
Re: Google is making private AI practical with homomorphic encryption
#246Earlier quoted context omitted.
It’s slightly better for LLMs because FHE is really bad at branches (it ends up essentially having to try both branches), making sorts nearly the worst possible thing to try since it’s all branches. In the case of AI most things are just addition and multiplication which can make some things faster since there aren’t as many branches. But we’re still nowhere near viability.
Sorting doesn't need any branches. For FHE you need to think like a circuit designer without indexing operations. In that situation your default sort is a sorting network, made out of nlogn conditional swaps.
Re: Google is making private AI practical with homomorphic encryption
#247I‘m new to this, but mildly skeptical. In complex agentic engineering, there are lots of intermediate steps that depend on each other. Even if you disregard the significant encryption cost, this makes it impractical. So seems like this will stay a niche.
Re: Google is making private AI practical with homomorphic encryption
#248I really want nobody to waste cycles on my AI than me. This is useless because now I need to pay for wasted inference AND encryption cycles on top of wire encryption.
This is where we believe Belfort can make a real difference: enabling organizations to compute on sensitive data while preserving strong privacy guarantees. And FHE doesn’t necessarily mean relying on Google, AWS, or Azure for encrypted compute. Companies can run FHE on their own infrastructure, allowing them to process their clients’ data privately while maintaining control over their systems and keys.
These applications are our initial focus, and over time, we aim to expand the range of use cases that FHE can unlock.
Re: Google is making private AI practical with homomorphic encryption
#249Earlier quoted context omitted.
Sorting doesn't need any branches. For FHE you need to think like a circuit designer without indexing operations. In that situation your default sort is a sorting network, made out of nlogn conditional swaps.
can you build a conditional swap in FHE in a small size though? FHE is always circuit like, ie no dynamic control flow anyway I think?
Bitwise: X = A&C | B&¬C, Y = A&¬C | B&C
Arithmetic: X = A*C + B*(1-C), Y = A*(1-C) + B*C
Edit: Or to put it another way, one of the most basic things you can make in a circuit is a multiplexer, and a conditional swap is two minimum size multiplexers next to each other.
Re: Google is making private AI practical with homomorphic encryption
#250The only question is do you trust Google? No…
But there is more to it. Teams like us at Belfort, we are working to make FHE practical for organizations that want to deploy it for their own use cases, including on infrastructure they control themselves. Even in these setups, FHE can enable applications that would otherwise be blocked by regulatory, privacy, or compliance requirements.