Valerie Gilchrist

(she/her)

Email: valerie.gilchrist@ulb.be // CV: here // Google Scholar: here

I am a PhD student at Université Libre de Bruxelles, working with Christophe Petit. I do research mostly in isogeny-based cryptography, either looking for algorithmic improvements to systems or investigating their security claims.

I did a Masters of Mathematics at the University of Waterloo with David Jao. My thesis was about using SQISign in an adaptor signature.

Publications and preprints

"Another Look at the Quantum Security of the Vectorization Problem with Shifted Inputs." Paul Frixons, Valerie Gilchrist, Péter Kutas, Christophe Petit. eprint.

"Further Connections Between Isogenies of Supersingular Curves and Bruhat-Tits Trees." Steven Galbraith, Valerie Gilchrist, Shai Levin, Ari Markowitz. eprint.

"Attacking trapdoors from matrix products." Thomas Decru, Tako Boris Fouotsa, Paul Frixons, Valerie Gilchrist, Christophe Petit. Communications in Cryptology, Volume 1, Issue 3 (2024). eprint.

"Solving the Tensor Isomorphism Problem for special orbits with low rank points: Cryptanalysis and repair of an Asiacrypt 2023 commitment scheme." Valerie Gilchrist, Laurane Marco, Christophe Petit, Gang Tang. CRYPTO 2024. eprint.

"Fast and Frobenius: Rational Isogeny Evaluation over Finite Fields." Gustavo Banegas, Valerie Gilchrist, Anaëlle Le Dévéhat, Benjamin Smith. LatinCrypt 2023. eprint.

"Efficient supersingularity testing over F_p and CSIDH key validation." Gustavo Banegas, Valerie Gilchrist, Benjamin Smith. MathCrypt 2022. eprint. Video from MathCrypt. Slides.

"An Isogeny-Based Adaptor Signature Using SQISign." (Masters thesis). Valerie Gilchrist. UWSpace 2022. pdf. Slides.

Upcoming Talks

  • "Attacking trapdoors from matrix products" at ArcticCrypt (August 2025).

    • Conferences and Invited Talks

  • "Solving the Tensor Isomorphism Problem for special orbits" at the University of Rennes, cryptography seminar (November 2024). Slides.
  • "Solving the Tensor Isomorphism Problem for special orbits" at the Universté Libre de Bruxelles, security seminar (May 2024).
  • Seminar talks at the University of Auckland, algebra group and graduate student group (March 2024).
  • "Computing rational isogenies from irrational kernel generators" at LatinCrypt (October 2023).
  • "Efficient supsersingularity testing" at SIAM Conference: Algebraic Geometry (July 2023).
  • "The State of Post-Quantum Cryptography" at Cyberus (July 2023). Slides.
  • "Computing rational isogenies from irrational kernel generators" at Isogeny Club (April 2023). Video. Slides.
  • "Efficient supsersingularity testing over F_p and CSIDH key validation" at Isogeny Days (September 2022). Video. Slides.
  • "Efficient supsersingularity testing over F_p and CSIDH key validation" at MathCrypt (August 2022).
  • "SAS: an adaptor signature from isogenies" at Inria Saclay (July 2022).
  • I have reviewed submissions on behalf of Crypto 2025, AfricaCrypt 2025, AsiaCrypt 2024, PQCrypto 2024, EuroCrypt 2023, AsiaCrypt 2023, AsiaCrypt 2023.
  • I've been a teaching assistant for the following courses at ULB : Intro to Python, Projects course.
  • I've been a teaching assistant for the following courses at UWaterloo : Applied cryptography, Mathematics of public key cryptography, Intro to combinatorics, Intro to geometry.
  • I've been a teaching assistant for the following courses at UToronto: Calculus 1,3, and 4; Linear algebra; Algebraic cryptography; Intro to logic; Intro to general relativity.


    • See @fjotographie for more cool pictures (not of me).