Question: Does tfhe-rs (plan to) support multiparty or multikey FHE?

[hu55a1n1]

What is the problem you want to solve and can not with the current version?
Very cool project! Thank you for the awesome work you guys are doing! 🥇

I wasn't able to find any mention of MP/MK FHE in the docs and examples.

• Is multiparty/multikey FHE supported?
• If not, do you plan to support it in the future?

Describe the solution you'd like

• Ideally multikey support - something I could use in a multi-client setting such that each client gets their own key.
• And the server is able to do computations involving ciphers from multiple clients.

Describe alternatives you've considered
I thought about solutions involving (TEE-based/proxy) reencryption, but that's far from ideal.

[jborfila]

Hey! Thanks for the comment, this is really appreciated :)

About the multi key stuff, or more generally multi users, this is not supported at the moment.

However, we are working on solutions based on threshold fhe, which will be available in 2024. This will be more efficient than existing multikeys based solutions, since using the same evaluation keys than the ones already in use!

We keep your issue opened until then ;)

[lastmjs]

Is the threshold fhe becoming available in 2024 in collabaration with the DFINITY Foundation?

[IceTDrinker]

hey apologies @lastmjs your question fell through the cracks with the summer break, we'll get back to you 🙂

[jborfila]

Hey @lastmjs, sorry for the delay!
Without commiting on what is going to be available in 2024, I suggest you to have a look to this paper (https://eprint.iacr.org/2023/815) is you are interested about Threshold FHE.
At the moment, the collaboration with DFINITY is related to research: you can have a look at this (https://eprint.iacr.org/2023/536) :)

[alfellati]

Hey, I'm working on something related to sMPC (to be specific, off-chain compute layer for general computation and storage, something like flux cloud using sMPC) and would like to use TFHE instead to make it more efficient, any leads on how to do that with this implementation?. Another question is when are you implementing the sidechannel attack mitigation?

[IceTDrinker]

hello @alfellati

when you say this implementation what are you referring to ?

As for the side channel attacks we are not yet stable, so unclear at the moment

[lastmjs]

Are there any updates on when in 2024 we will have some kind of threshold of multikey support for TFHE-rs?

[JamesMenetrey]

Hello @jborfila!

Have you progressed on the threshold work? Is there any ETA or early work (from another branch) to play with?

Thanks!