Round 3 of the NIST additional signatures process announced! 🎉 And SQIsign is part of it!! ⛷️⛷️

Looking forward to AM-PQC 2026, the Workshop on Algebraic Methods in Post-Quantum Cryptography this August in Macedonia! pqcrypto.cs.ru.nl/ampqc/ Stipends for students are available. Apply before May 4th!

I'm beginning to feel more and more that the meaning of the ‘∞’ in “∞-categories” is that you can only explain what an ∞-category is to someone who already knows what an ∞-category is.

Writeup of the crypto-challenge MonoDOOM ETERNAL from #KalmarCTF - A follow up from last-years MonoDOOM challenge, this time with botched side-channel protection! jonathke.github.io/monoDOOM-ETE...

🔽 So, @jeanas.bsky.social and I are please to announce a new preprint in computability, in which we show that the Turing degrees can be embedded upside down in (what we call) the “Arthur-Nimue-Merlin degrees”. The paper opens with a riddle, which I hope will be of interest!

At my age I am no longer ashamed to confess that I have absolutely zero intuition about what a Gorenstein ring looks like: mathoverflow.net/q/509373/17064

We still have a few spots left at MaGIC! Registration closes this week... Hurry up if you want to be on top of all the latest news on Cryptographic Group Actions! magic-workshop.github.io

Thomas and I looked at directed isogeny graphs! In dim 1, we often ignore directedness, as there are only 2 "problematic" curves. Not so in dim 2: we analyze the action of automorphisms on level structures and the resulting directed graphs. Crucial: Directed (2,2)-graphs looks Ramanujan after all!

TL;DR: - SQIsign more general than initially thought. - More space for protocol design! - SQIsign NIST v2 still the best signature, by a small margin. Ilinca already foreshadowed some of this in www.youtube.com/watch?v=5tGb..., though that's a different POV we're still writing up.

We're organizing a workshop on cryptographic group actions bringing together the isogeny and code communities. The workshop is just before Eurocrypt, a quick train away from Rome in the beautiful Marche. Early registration ends this week, so grab your spot soon! magic-workshop.github.io

Breaking digital signatures from tropical matrix semirings (Alessandro Sferlazza) ia.cr/2026/327

Continuation and end of the thread started here: bsky.app/profile/dami... # Part 4: Speculations Previously: - Part 1: CSIDH bsky.app/profile/dami... - Part 2: SIDH bsky.app/profile/dami... - Part 3: MIKE bsky.app/profile/dami...

Continuation of the thread started here: bsky.app/profile/dami... # Part 3: MIKE Previously: - Part 1: CSIDH bsky.app/profile/dami... - Part 2: SIDH bsky.app/profile/dami...

Continuation of the thread started here: bsky.app/profile/dami... # Part 2: SIDH Previously: # Part 1: CSIDH bsky.app/profile/dami...

I am very happy to announce that thanks to the hard work of many people (The "MIKE Team"), we now have a working implementation in SageMath of MIKE (Module Isogeny Key Exchange).

New year, new pairing

Interesting question: mathoverflow.net/q/506367/

Each time I try to use the nLab to look up something it is the same experience: the first sentence has ten words I don't understand, so I recursively open the corresponding links, and before long I end up with 100 tabs open, 30 research papers, and 15 different references to the books by Lurie...

Leçon inaugurale de Pascale Senellart @college-de-france.fr @psl-univ.bsky.social www.college-de-france.fr/fr/agenda/le...

And now we are famous: www.nytimes.com/2025/11/21/w... - congratulations to all colleagues who made the NYT (both through quotes, by playing a role, or by being on this picture)

If anyone wants to learn a broad overview of computability theory and Turing degrees, I recommend Soare's 2016 book “Turing Computability: Theory and Applications” (not to be confused with his 1987 book, “Recursively Enumerable Sets and Degrees”, which is much denser!).

I thought the notion of “sheaf for a Lawvere-Tierney topology” was a very complicated one, but I realized it's actually not so complicated, and it can be defined completely internally (i.e., you don't need to know what a topos is, just how constructive math works). •1/7

I'm happy to hear that Egbert Rijke's book “Introduction to Homotopy Type Theory” is finally published by Cambridge University Press! www.cambridge.org/us/universit...

TL;DR: See title 🥳

The Isogeny Club Season 7 starts today! At 5pm CEST, Bruno Sterner will talk about finding large smooth twins from short lattice vectors. More details at isogeny.club

Announcing The Isogeny Problems! A curated list of the seven foremost unsolved problems in isogeny-based cryptography. Solving one of these profound questions would mark a monumental advance, and as a resolver you'd get eternal honor and epic rewards! Full list: isogeni.es/problems

TL;DR: we solve norm equations in a better way and get around a 2x improvement to IdealToIsogeny routines crucial in both SQIsign and PRISM.

Registration for the Leuven Isogeny Days 6 is now open! 📅 10–12 Sept 2025 @ KU Leuven Morning: research talks Afternoon: brainstorming sessions More info: www.esat.kuleuven.be/cosic/projec... #isogeny #isocrypt #erc #postquantum

We (finally) published all the material from this course on SQIsign, including lecture slides and exercise sheets for the Sage laboratory. Available here: github.com/andreavico/S...

📢 #1MinuteAvec ... ⏰ Alice Pellet-Mary au pays des codes secrets et de la #cryptographie. Portrait à découvrir de cette chercheuse de l'équipe #Canari du Centre #Inria de l' @univbordeaux.bsky.social qui partage avec nous son #parcours et son #métier ! 👉 youtu.be/LKRy8bO5x8E?...

A kind of social variant of the man-in-the-middle attack: 🧵🔽

New work: we explain cubical arithmetic in simple terms to show you how easy it is to compute pairings. Essentially, you only need to know the Montgomery ladder! As a bonus, pairings from cubical arithmetic are faster than those from Miller's loop for applications in isogeny-based cryptography.

Yes! RWC ❤️ Number Theory. Congrats to the CADO-NFS team!

Registration to the SQIparty is open, free, and we have a first sketch of a program! www.cig.udl.cat/SQIparty2025... Register and plan your travel quickly: the rooms are reserved only until Thursday! See you in Lleida!

🔊 Le 19/03 c'est la journée internationale du #Canari 🪶! Le jour idéal pour vous partager des infos sur notre équipe (du même nom) qui conçoit des #algorithmes pour la sécurité des données au service de la #cryptographie #postquantique 🌐! ↪️ www.inria.fr/fr/canari-pr... ↪️ www.inria.fr/fr/canari

> claims no new results > adds in a tiny new result anyway > ??? anyway, enjoy the read!

Fancy some isogeny crypto? Join us for a 3-day workshop on isogeny-based cryptography in Lleida, Catalonia, April 28-30 www.cig.udl.cat/icrypto2025_... Brought to you by ULleida's Cryptography+Graphs group, the SQIsign team and friends! Registration and program coming soon Registration is free!

GG everyone who played #KalmarCTF 2025! Writeups for my two challs: MonoDOOM: jonathke.github.io/monoDOOM A chal based on a sick sidechannel attack by @damienrobert.bsky.social ! Not-so-complex multiplication: jonathke.github.io/not-so-complex An easy chal based on complex multiplication.

Absolutely thrilled for season six of the Isogeny Club (isogeny.club) starting February 25th by a talk by Abel Laval!

Really excited to finally share PRISM, a new isogeny-based signature 🥳 joint work with lots of awesome people. eprint.iacr.org/2025/135

Pour la Journée internationale de la #protection des #données, coup de projecteur sur les travaux novateurs de l'équipe-projet #Canari. 🧐 Son domaine de recherche ? Les protocoles et #algorithmes de #cryptographie #postquantique ! 👉 www.inria.fr/fr/securite-... cc @damienrobert.bsky.social

Le #logiciel PARI/GP, système de calcul formel pour la théorie des nombres, a reçu le #Prix science ouverte du #logiciel libre 2024 pour la catégorie « communauté ». 👋 à Aurel Page de l'équipe #Canari et aux scientifiques de l' #IMB impliqués ! t.co/oWqHxweG24 cc @damienrobert.bsky.social

I was today years old when I realized we can build twists of X as a pullback from the classifying stack BAut(X). Why didn't anyone ever tell me?! This simplifies so many arguments about twists! (Shamelessly copying Krijn's post: bsky.app/profile/krij...)

Nice paper! arxiv.org/abs/2411.11566

#HelloESR: I am a researcher at Inria Bordeaux, head of the Canari team canari.math.u-bordeaux.fr, hosted at the Institut de Mathématiques de Bordeaux. I work on algorithmic number theory, notably on abelian varieties and their moduli spaces, and their applications to cryptography (#isogenies).

First, let me comment a bit on the article eprint.iacr.org/2024/1582, written with my phd student Nicolas Sarkis. This is a follow up to our article on computing 2-isogenies between Kummer lines: eprint.iacr.org/2024/037

Following Twitter's great migration, I had made an account at @[email protected], but never posted there. Let me try here in bsky which seems to have more momentum.