Ϲhristian Knabenhans

PhD student @EPFL; ex-@ETH.

Taking privacy-enhancing crypto (SNARKs, FHE & co) from theory to practice, and back.

🏳️‍🌈

[Ϲhristian Knabenhans @cknabs]

Finally, we're thinking about high-assurance. We're working on a formally verified constant-time implementation of client-side FHE operations (in Jasmin+EasyCrypt), and we're exploring how to best use high-assurance tools (hax/hacspec, Jasmin, Lean) for lattirust. Stay tuned!

[Ϲhristian Knabenhans @cknabs]

I'm happy to finally open-source lattirust, a library for lattice-based zero-knowledge/succinct arguments! Lattirust is somewhat like arkworks, but for lattices; and like lattigo, but for arguments.

➔ https://t.co/Kb41v4UOGQ

[Ϲhristian Knabenhans @cknabs]

At the moment we're relying on existing lattice estimators to set concrete parameters, but Xavier Marchon did a semester project to write a SIS-specific, Rust lattice estimator, which will be directly integrated in lattirust.

[Ϲhristian Knabenhans @cknabs]

Read the paper on ePrint https://t.co/OzfQTa9tcJ, my blog post at https://t.co/OhxtVB6lzN, or watch @HyperD3rp’s presentation at Asiacrypt! I’ll also make the code open-source soon™, along with a lot more lattice implementations. Stay tuned! (8/8)

[Ϲhristian Knabenhans @cknabs]

Lova 💕 (aka lattice Nova): @HyperD3rp, @GiacomoGenzi, @KhanhCrypto and I built a folding scheme from (unstructured) lattice assumptions, which will be presented at Asiacrypt this week! (1/8)

[Ϲhristian Knabenhans @cknabs]

Finally, an open problem:
Lova is very algebraic but uses plain SIS, Latticefold uses MSIS but relies on sumcheck, which is a powerful tool (too powerful?). Can we get a scheme that uses MSIS and barely does more than a single random linear combination? (7/8)

[Ϲhristian Knabenhans @cknabs]

If you're applying for a PhD in applied crypto/system security/privacy this year, you should absolutely consider applying to @anwarhit's new lab at UoT!

She's a brilliant researcher and a wonderful advisor, don't miss this opportunity to work with her.

[Tom Gur @TomGur]

Excited to share this new paper with Jack O'Connor and @_nickspoon! We improve our ZK-PCP construction to cover all of NEXP (with exponential proofs), scale it to NP with polynomial proofs, and obtain O(1)-locality via composition--yielding a ZK analogue of the PCP theorem. 1/3

[Ϲhristian Knabenhans @cknabs]

We're starting a study group on Alessandro Chiesa and Eylon Yogev's https://t.co/3n6pOvm6NK on the ZK Hack Discord!
Join us this Thursday at 6pm CET for an intro by Alessandro: https://t.co/F2jA6lO0C5

[EPFL Computer and Communication Sciences @ICepfl]

Make the Most of Your Summer by joining us for Summer@epfl 2025!!

📡To apply go here https://t.co/cbx7ZOxPLM
⏳The application deadline for all students is on the Sunday closest to 1st December (anywhere on Earth).

@EPFL_en @EPFL_AI_Center @EPFL_Imaging

[OpenFHE - Open Source Fully Homomorphic Encryption @OpenFHE_org]

Happy to share this great project from @cknabs that builds off @OpenFHE_org with the additional ability to prove the correct evaluation of FHE circuits using a (zero-knowledge) succinct non-interactive argument of knowldege ((zk)SNARK). Open-source FTW!
https://t.co/VOgmUhIbWv

[Trail of Bits @trailofbits]

Is there a quantum computer in the NSA's basement? Does there need to be to justify PQC?
Read the blog: https://t.co/K2a6NMI7YO