News

Here is a list of things going on in my professional life.


  • I gave a talk about the computing traces of endomorphisms, joint project with Travis Morrison, Lorenz Panny, and Michael Wills, at the ISOCRYPT workshop in Leuven, Belgium. Video recording should be available later.
  • I attended the 10th Heidelberg Laureate Forum.
    It was a great experience and opportunity to interact with young researchers and many senior celebrated figures in my field. I would encourage everyone to apply to any of the future instances.
    picture of Jana
  • I gave a talk about the Deuring for the people! collaboration with Jonathan Komada Eriksen, Lorenz Panny, and Mattia Veroni, at the LuCaNT conference, July 10-14, 2023 in Providence, RI. The slides and the video are available at the ICERM website.
  • I gave a talk about SALSA PICANTE at the AICRYPT workshop collocated with Eurocrypt 2023
  • Finished up the fun project SALSA PICANTE: a machine learning attack on LWE with binary secrets
    Cathy Li, Jana Sotáková, Emily Wenger, Mohamed Malhou, Evrard Garcelon, Francois Charton, and Kristin Lauter
    eprint: Report 2023/340; arxiv: arXiv:2303.04178.
    Training transformers to learn from LWE samples to try to recover the secrets. Main contributions: reduced data requierement to linear number of samples (machine learning models use millions of samples to learn), added a preprocessing step that turns the samples into ones from which the transformer learns better; novel cross-attention mechanism that can read off the secret from the transformer itself.
    Pushed the dimensions and hamming weights to n=350 and Hamming weights ~n/10. Still long way to go to threaten real-world schemes, but this is a massive improvement over the previous Salsa paper (n=128 with h=3)!
  • Disorientation faults in CSIDH were accepted to Eurocrypt 2023! The preprint is here ePrint 2022/1202. This is joint work with Gustavo Banegas, Juliane Krämer, Tanja Lange, Michael Meyer, Lorenz Panny, Krijn Reijnders, and Monika Trimoska.
    Summary: While this is a physical attack (specifically, a fault-injection attack), we do exploit a lot of the inherent structure present in computing isogenies. Specifically, our threat model assumes we can flip the direction of some isogeny steps during the class group action computation. We overexamine what information this leaks - and we show that in almost all implementations, one can recover the whole secret key from a very modest number of successful faults!
  • Finished my lovely collaboration with Jonathan Komada Eriksen, Lorenz Panny and Mattia Veroni on making the Deuring correspondence more accessible - and easy to work with. Our preprint is public on eprint, the code is in a GitHub repo friends-of-quaternions/deuring.
    Summary: We speed up the computation of the Deuring correspodence in general characteristic, using a couple of neat tricks to work with torsion points over extensions -- and selecting which torsion points to work with. We give Sage code for everything: the main parts are the KLPT and IdealToIsogeny algorithms.
  • From December 2022 until March 2023, I will be an intern for Kristin Lauter at Meta AI.
  • I attended the Leuven Isogeny Days 3 workshop.
  • I made a poster for ANTS XV presenting our new fault attack on CSIDH-like group action. Here are the two separate pictures for the neighbourhood graphs and here is the full graph. We will put the paper online shortly! The paper.
  • I am attending the PCMI 2022 Summer Session, as a Teaching Assistant for the course on isogenies given by Kristin Lauter in the second week of the Graduate Summer School!
    Course materials (very similar to the 2021 online version) will be available here.
  • On April 5, I gave a talk at the ACCESS seminar talking about CTIDH: constant time CSIDH. You can check the slides.
    Here are some expository notes I wrote about CTIDH to go with my talk at the ACCESS seminar, focusing on the math ideas behind CTIDH.
    • For more (mostly older), see also the news section.
  • From December 2022 until March 2023, I will be an intern for Kristin Lauter at Facebook AI Research.
  • We finished our paper Disorientation faults in CSIDH, available as ePrint 2022/1202. Joint work with Gustavo Banegas, Juliane Krämer, Tanja Lange, Michael Meyer, Lorenz Panny, Krijn Reijnders, and Monika Trimoska.
  • I attended the Leuven Isogeny Days 3 workshop.
  • I made a poster for ANTS XV presenting our new fault attack on CSIDH-like group action. Here are the two separate pictures for the neighbourhood graphs and here is the full graph. We will put the paper online shortly!
  • I am attending the PCMI 2022 Summer Session, as a Teaching Assistant for the course on isogenies given by Kristin Lauter in the second week of the Graduate Summer School!
    Course materials (very similar to the 2021 online version) will be available here.
  • On April 5, I gave a talk at the ACCESS seminar talking about CTIDH: constant time CSIDH. You can check the slides.
    Here are some expository notes I wrote about CTIDH to go with my talk at the ACCESS seminar, focusing on the math ideas behind CTIDH.
  • In March 2022, I attended Isogeny-based Cryptography Workshop and gave a talk about Breaking DDH using genus theory. Slides here.
  • With WIQD, we are organizing a Annual WIQD Symposium: “Defying Gravity” on May 3, 2022! Sign up here!
  • My paper "Adventures in Supersingularland" has been published in Open Access at Experimental Mathematics.
    https://doi.org/10.1080/10586458.2021.1926009 This is joint work with Sarah Arpin, Catalina Camacho-Navarro, Kristin Lauter, Joelle Lim, Kristina Nelson and Travis Scholl.
  • I recorded a talk for the CTIDH paper at CHES 2021. The video is available here on Youtube, the paper is available here, and the paper and software in their latest version are also available at ctidh.isogeny.org.
  • I lectured about the DDH paper at the Isogeny School. Notes are available here. Scribbles from Aug 12 sessions: morning session and evening session.
  • During July 26-30, 2021, I was TAing for Kristin Lauter at the PCMI Graduate Summer School 2021. Videos from the lectures will be available at the PCMI YouTube channel.
    Materials are available here.
  • Our paper "CTIDH: Faster constant-time CSIDH" is online! A collaboration with Gustavo Banegas, Daniel J. Bernstein, Fabio Campos, Tung Chou, Tanja Lange, Michael Meyer, Benjamin Smith.
    Check out the website with the paper and the software.
    The paper is also on eprint as Report 2021/633.

  • Our paper "Explicit connections between supersingular isogeny graphs and Bruhat--Tits trees" with Laia Amorós, Annamaria Iezzi, Kristin Lauter and Chloe Martindale is on eprint!
    The current version is also accessible here.
    I have given two talks about the paper and you can see my exposition in these notes here. Please contact me with any comments!

  • I will be a TA at the (online) PCMI 2021 Graduate Summer School (July 26-30, 2021) for the course of Kristin Lauter on Supersingular Isogeny Graphs in Cryptogprahy.
  • In Spring 2021, I am running a reading group at QuSoft on quantum algorithms for isogeny problems.
  • (7/23) I gave a talk at the student-organized ANTS summer school on "Elliptic curves, isogenies, and endomorphism rings". The talk is available on Youtube
    and the write-up is here (rough draft but includes references and comments).
  • (6/03) I gave a talk at the Linfoot number theory seminar in Bristol. The slides or write-up
  • (6/03) I will be at the Isogeny-based cryptography summer school in Bristol, December 14-18 2020.
  • (3/10) I will be giving a talk about my work in the afternoon QSC session of the Dutch Mathematical Congress (NMC). Links to the abstract and for the conference schedule. Unfortunately, the NMC has been cancelled but might still happen at a different date.
  • (2/14) Breaking DDH with genus theory with Wouter Castryck and Fre Vercauteren is out! The eprint article is here.
    For a cool explanation see this blogpost by Steven Galbraith or Luca de Feo's take on Twitter!
  • (1/20) I will be a TA for the course on Supersingular Isogeny Graphs by Kristin Lauter during the Park City Mathematical Institute 2020 in July 2020. (7/23) The program has been rescheduled to July, 2022.
  • I was a visiting graduate student at the The Quantum Wave in Computing semester program at the Simons Center from Jan 20 to Feb 7, 2020.