Theses

1. Random Walks in Number-theoretic CryptologyHDR Thesis · manuscriptPresented on 29 August 2024 at École Normale Supérieure de Lyon (ENS Lyon), France
2. Arithmetic and geometric structures in cryptographyPhD Thesis · manuscriptPresented on 30 November 2018 at École Polytechnique Fédérale de Lausanne (EPFL), SwitzerlandSupervised by Prof. Arjen K. Lenstra and Dr. Robert Granger

Preprints

1. The supersingular isogeny problem in time and memory p^1/3+o(1)Cryptology ePrint Archive 2026 · preprint
2. Forensic categories: a framework for SQIsign-like primitivesWith Andrea Basso, Luca De Feo, Sikhar Patranabis and Ilinca RadulescuCryptology ePrint Archive 2026 · preprint
3. Rigorous Methods for Computational Number TheoryWith Koen de Boer and Alice Pellet-MaryCryptology ePrint Archive 2025 · preprint
4. On the computation of endomorphism rings of abelian surfaces over finite fieldsWith Samuele Anni, Gaetan Bisson, Annamaria Iezzi and Elisa Lorenzo GarcíaarXiv 2025 · preprint
5. Understanding and improving the Castryck-Decru attack on SIDHUnpublished note, 2022 · preprint
6. Lower bounds for the depth of modular squaringWith Ryan WilliamsCryptology ePrint Archive 2020 · preprint

Peer-reviewed articles

1. A computational framework for principally polarized abelian varieties and applicationsWith Maria Corte-Real Santos and Etienne PiaseckiTo appear at Asiacrypt 2026 · preprint
2. Average hardness of SIVP for module lattices of fixed rankWith Koen de Boer, Aurel Page and Radu TomaSTOC 2026 · preprint
3. Unconditional foundations for supersingular isogeny-based cryptographyWith Arthur Herlédan Le MerdyTCC 2025 · preprint
4. A Complete Security Proof of SQIsignWith Marius A. Aardal, Andrea Basso, Luca De Feo and Sikhar PatranabisCrypto 2025 · preprint
5. PEGASIS: Practical Effective Class Group Action using 4-Dimensional IsogeniesWith Pierrick Dartois, Jonathan Komada Eriksen, Tako Boris Fouotsa, Arthur Herlédan Le Merdy, Riccardo Invernizzi, Damien Robert, Ryan Rueger and Frederik VercauterenCrypto 2025 · preprint
6. The supersingular endomorphism ring problem given one endomorphismWith Arthur Herlédan Le MerdyIACR Communications in Cryptology, Volume 2, Issue 1 (2025) · preprint
7. PRISM: Simple And Compact Identification and Signatures From Large Prime Degree IsogeniesWith Andrea Basso, Giacomo Borin, Wouter Castryck, Maria Corte-Real Santos, Riccardo Invernizzi, Antonin Leroux, Luciano Maino, Frederik VercauterenPKC 2025 · preprint · extended versionBest paper award PKC 2025
8. SQIsign2D-West: The Fast, the Small, and the SaferWith Andrea Basso, Pierrick Dartois, Luca De Feo, Antonin Leroux, Luciano Maino, Giacomo Pope and Damien RobertAsiacrypt 2024 · preprint
9. Cryptanalysis of Algebraic Verifiable Delay FunctionsWith Alex Biryukov, Ben Fisch, Gottfried Herold, Dmitry Khovratovich, Gaëtan Leurent and María Naya-PlasenciaCrypto 2024 · preprint
10. Computing isogenies between finite Drinfeld modulesIACR Communications in Cryptology, Volume 1, Issue 1 (2024) · preprint
11. The supersingular Endomorphism Ring and One Endomorphism problems are equivalentWith Aurel PageEurocrypt 2024 · preprint
12. SQISignHD: new dimensions in cryptographyWith Pierrick Dartois, Antonin Leroux and Damien RobertEurocrypt 2024 · preprintBest paper award Eurocrypt 2024
13. Finding orientations of supersingular elliptic curves and quaternion ordersWith Sarah Arpin, James Clements, Pierrick Dartois, Jonathan Komada Eriksen and Péter KutasDesigns, Codes and Cryptography (2024) · preprint · open access
14. Ideal-SVP is hard for small-norm uniform prime idealsWith Joël Felderhoff, Alice Pellet-Mary and Damien StehléTCC 2023 · preprint
15. A direct key recovery attack on SIDHWith Luciano Maino, Chloe Martindale, Lorenz Panny and Giacomo PopeEurocrypt 2023 · preprintTop-3 paper Eurocrypt 2023
16. New algorithms for the Deuring correspondence: toward practical and secure SQISign signaturesWith Luca De Feo, Antonin Leroux, and Patrick LongaEurocrypt 2023 · preprint
17. Supersingular curves you can trustWith Andrea Basso, Giulio Codogni, Deirdre Connolly, Luca De Feo, Tako Boris Fouotsa, Guido Maria Lido, Travis Morrison, Lorenz Panny and Sikhar PatranabisEurocrypt 2023 · preprint
18. SCALLOP: scaling the CSI-FiShWith Luca De Feo, Tako Boris Fouotsa, Péter Kutas, Antonin Leroux, Simon-Philipp Merz and Lorenz PannyPKC 2023 · preprint
19. A note on the low order assumption in class group of an imaginary quadratic number fieldsWith Karim Belabas, Thorsten Kleinjung and Antonio SansoMathematical Cryptology (2023) · preprint
20. On the decisional Diffie-Hellman problem for class group actions on oriented elliptic curvesWith Wouter Castryck, Marc Houben and Frederik VercauterenANTS-XV, Fifteenth Algorithmic Number Theory Symposium (2022) · preprint
21. Orientations and the supersingular endomorphism ring problemEurocrypt 2022 · preprint
22. Discrete logarithms in quasi-polynomial time in finite fields of fixed characteristicWith Thorsten KleinjungJournal of the American Mathematical Society, Volume 35, Number 2 (2022) · preprint
23. The supersingular isogeny path and endomorphism ring problems are equivalentFOCS 2021 · preprint
24. Séta: Supersingular Encryption from Torsion AttacksWith Luca De Feo, Cyprien Delpech de Saint Guilhem, Tako Boris Fouotsa, Péter Kutas, Antonin Leroux, Christophe Petit, Javier SilvaAsiacrypt 2021 · preprint
25. Computation of a 30750-Bit Binary Field Discrete LogarithmWith Robert Granger, Thorsten Kleinjung, Arjen K. Lenstra and Jens ZumbrägelMathematics of Computation, Volume 90, Number 332 (2021) · preprint
26. Mildly short vectors in cyclotomic ideal lattices in quantum polynomial timeWith Ronald Cramer and Léo DucasJournal of the ACM, Volume 68, Issue 2 (2021) · preprint
27. SQISign: compact post-quantum signatures from quaternions and isogeniesWith Luca De Feo, David Kohel, Antonin Leroux and Christophe PetitAsiacrypt 2020 · preprintBest paper award Asiacrypt 2020
28. Efficient Verifiable Delay FunctionsJournal of Cryptology 2020 · paper
29. Random self-reducibility of Ideal-SVP via Arakelov random walksWith Koen de Boer, Léo Ducas and Alice Pellet-MaryCrypto 2020 · preprint
30. On the shortness of vectors to be found by the Ideal-SVP quantum algorithmWith Léo Ducas and Maxime PlançonCrypto 2019 · preprint
31. Efficient verifiable delay functionsEurocrypt 2019 · preprintBest young researcher paper Eurocrypt 2019
32. Horizontal isogeny graphs of ordinary abelian varieties and the discrete logarithm problemWith Dimitar JetchevActa Arithmetica 187 (2019) · preprint
33. A new perspective on the powers of two descent for discrete logarithms in finite fieldsWith Thorsten KleinjungANTS-XIII, Thirteenth Algorithmic Number Theory Symposium (2018) · preprint
34. Generating subgroups of ray class groups with small prime idealsANTS-XIII, Thirteenth Algorithmic Number Theory Symposium (2018) · preprint
35. Isogeny graphs of ordinary abelian varietiesWith Ernest Hunter Brooks and Dimitar JetchevResearch in Number Theory 3 (2017) · open access
36. Loop-abort faults on supersingular isogeny cryptosystemsWith Alexandre GélinPQCrypto 2017 · preprint
37. Short Stickelberger class relations and application to Ideal-SVPWith Ronald Cramer and Léo DucasEurocrypt 2017 · preprintTop-3 paper Eurocrypt 2017
38. Trustworthy public randomness with sloth, unicorn, and trxWith Arjen K. LenstraInternational Journal of Applied Cryptography (2016) · preprint
39. Malleability of the blockchain’s entropyWith Cécile PierrotArcticCrypt 2016 · preprint
40. Ciphertext-policy attribute-based broadcast encryption with small keysWith Pascal JunodICISC 2015 · preprint

Talks

1. The supersingular isogeny problem in cube-root timeThe Isogeny Club, Season 9, online (September 2026) · video
2. The supersingular isogeny problem in time and memory p^1/3+o(1)Leuven Isogeny Days 7, Leuven, Belgium (September 2026) · slides · notes
3. Random walks in number-theoretic cryptologyMOSS, the Mathematics Online Seminar Series (May 2026) · video
4. Rigorous Methods for Computational Number TheoryIntercity Number Theory Seminar, Amsterdam, The Netherlands (April 2026)
5. Fondements mathématiques de la cryptographie post-quantiqueJournée Crypto-Maths, Institut Henri Poincaré, Paris, France (March 2026)
6. On the equivalence between EndRing and OneEndAtelier Melodia, Laval, France (January 2026)
7. An introduction to isogeny-based cryptographyThe SQIparty, a workshop on isogeny-crypto, Lleida, Spain (April 2025) · slides
8. Cryptologie, théorie des nombres, et marches aléatoiresMatinée scientifique du département de mathématiques de l'ENS de Lyon, France (April 2025)
9. Recent advances in isogeny-based cryptographyOberwolfach Workshop on Cryptography, Germany (January 2025)
10. SQIsignHD and the HD revolutionWorkshop on emerging topics in design and cryptanalysis of post-quantum schemes, Institut Henri Poincaré, Paris, France (November 2024) · slides
11. SQIsignHD: Sqiing in higher dimensionsECC 2024, 25th Workshop on Elliptic Curve Cryptography, Taipei, Taiwan (October 2024) · slides
12. Computational Foundations of Isogeny-Based CryptographyECC 2024, Autumn School on Isogenies, Taipei, Taiwan (October 2024) · slides
13. Foundations of isogeny-based cryptographyMathematics for post-quantum cryptanalysis, Budapest, Hungary (August 2024) · slides
14. Foundations of isogeny-based cryptographyNormandie 2024, Caen, France (July 2024) · slides
15. The Supersingular Endomorphism Ring and One Endomorphism Problems Are EquivalentEurocrypt 2024, Zurich, Switzerland (May 2024) · slides
16. SQIsignHDCAIPI Symposium, Rennes, France (April 2024) · slides
17. Isogeny-based cryptography, a biased introductionCAIPI Symposium, Rennes, France (April 2024) · slides
18. Ideal-SVP is Hard for Small-Norm Uniform Prime IdealsTCC 2023, Taipei, Taiwan (December 2023) · slides · video
19. Interpolating isogeniesSeminar AMAC: CASC, Laboratoire Jean Kuntzmann, Grenoble, France (December 2023) · slides
20. The supersingular Endomorphism Ring and One Endomorphism problems are equivalentSéminaire d'arithmétique de Lyon, ENS Lyon, France (November 2023)
21. Interpolating isogeniesSéminaire d'arithmétique de Lyon, ENS Lyon, France (October 2023)
22. The supersingular Endomorphism Ring and One Endomorphism problems are equivalentGeometry Seminars at Tor Vergata, Rome, Italy (October 2023)
23. Interpolating isogenies, and applicationsRTCA 2023, Recent Trends in Computer Algebra, IHP, Paris, France (September 2023) · slides
24. Isogeny-based cryptography after The SnapPQCrypto, College Park, USA (August 2023) · slides · video
25. SQIsign HD: SQIing in higher dimensionsSIAM Conference on Applied Algebraic Geometry, online (August 2023)
26. Supersingular curves You can TrustCOUNT, COmputations and their Uses in Number Theory, Eindhoven, The Netherlands (July 2023)
27. Courbes elliptiques supersingulières en cryptographieSéminaire d'arithmétique de Lyon, ENS Lyon, France (February 2023)
28. Hard problems for isogeny-based cryptographySéminaire C2, Lyon, France (January 2023)
29. Reductions between hard isogeny problemsCIAO seminar, Bordeaux, France (December 2022)
30. Reductions between hard isogeny problemsLeuven Isogeny Days 3, Leuven, Belgium (September 2022) · video
31. Hard problems for isogeny-based cryptographySelected Areas in Cryptography (SAC 2022), Windsor, Canada (August 2022)
32. Hard problems for isogeny-based cryptographyCryptology seminar at IAI, TCG CREST, online (June 2022)
33. Hard problems for isogeny-based cryptographyJNIM 2022, Journées Nationales du GDR IM, Lille, France (March 2022) · video
34. SQISign: compact post-quantum signature from quaternions and isogeniesWorkshop on Isogeny-Based Cryptography, Birmingham, United Kingdom (March 2022)
35. Ideal lattices and the Arakelov class groupCHARM seminar, online (March 2022)
36. The supersingular isogeny path and endomorphism ring problems are equivalentCOSIC seminar, KU Leuven, Belgium (November 2021)
37. SQISign: compact post-quantum signature from quaternions and isogeniesLFANT seminar, Bordeaux, France (November 2021) · slides
38. SQISign: compact post-quantum signature from quaternions and isogeniesSIAM Conference on Applied Algebraic Geometry, online (August 2021) · slides
39. Hasard ou manipulation ? Peut-on tirer au sort et prouver que seul le hasard est maître ?Unithé ou café, Inria Bordeaux, online (June 2021)
40. SQISign: compact post-quantum signature from quaternions and isogeniesAriC Seminar, ENS Lyon, online (March 2021) · slides
41. Verifiable delay functionsBlockchain Seminar, Monash Blockchain Technology Centre, online (September 2020) · slides
42. New Reductions and Algorithms for Ideal Lattices via Arakelov Random WalksLattices: Geometry, Algorithms and Hardness, Simons Institute, Berkeley, USA (February 2020) · video
43. Discrete logarithms in quasi-polynomial time in finite fields of small characteristicSéminaire de Théorie des Nombres, Université de Bordeaux, France (February 2020) · slides
44. Verifiable delay functionsConférence de lancement de l'ANR Ciao, Université de Bordeaux, France (February 2020) · slides
45. Discrete logarithms in quasi-polynomial time in finite fields of small characteristicECC 2019, 23rd Workshop on Elliptic Curve Cryptography, Bochum, Germany (December 2019) · slides
46. Discrete logarithms in quasi-polynomial time in finite fields of small characteristicDiamant symposium, Utrecht, The Netherlands (November 2019) · slides
47. Discrete logarithms in quasi-polynomial time in finite fields of small characteristicApplied Crypto Group Seminar, Université du Luxembourg (November 2019) · slides
48. Discrete logarithms in quasi-polynomial time in finite fields of small characteristicProtocol Labs Journal Club (October 2019) · slides
49. Discrete logarithms in quasi-polynomial time in finite fields of small characteristicAriC Seminar, ENS Lyon, France (October 2019) · slides
50. Verifiable delay functionsEi/Ψ Crypto Working Group, Utrecht, The Netherlands (September 2019) · slides
51. Horizontal isogeny graphs: analytic methods and mixing propertiesSIAM conference on applied algebraic geometry, Bern, Switzerland (July 2019)
52. Quantum algorithms for finding short vectors in ideal lattices2nd QSC General Assembly, Amsterdam, The Netherlands (June 2019) · slides
53. The discrete logarithm problem in finite fields of small characteristicAlgebra, geometry and number theory seminar, Leiden University, The Netherlands (April 2019) · slides
54. The discrete logarithm problem in finite fields of small characteristicMathematical foundations of asymmetric cryptography, winter school, Aussois, France (March 2019) · slides
55. A hybrid verifiable delay functionBlockchain Research workshop at Stanford, CA, USA (February 2019)
56. Isogeny graphs of ordinary abelian varietiesSéminaires de l'Institut Fourier, Grenoble, France (December 2018)
57. Horizontal isogeny graphsAriC's Lattice and Crypto Session, ENS Lyon, France (December 2018)
58. An efficient verifiable delay functionEthereum Foundation and Stanford Center for Blockchain Research workshop at Stanford, CA, USA (August 2018)
59. Horizontal isogeny graphs of ordinary abelian varieties and the discrete logarithm problemSéminaire de Cryptographie, Rennes, France (February 2018) · slides
60. Mildly short vectors in cyclotomic ideal lattices in quantum polynomial timeCARAMBA seminar, Nancy, France (January 2018) · slides
61. Isogeny graphs of ordinary abelian varietiesECC 2017, 21st Workshop on Elliptic Curve Cryptography, Nijmegen, The Netherlands (November 2017) · slidesBest presentation award
62. Isogeny graphs of ordinary abelian varietiesLFANT seminar, Bordeaux, France (May 2017) · slides
63. Graphes d'isogénies de variétés abéliennes ordinairesJournées Codage et Cryptographie, La Bresse, France (April 2017) · slides (french)
64. Randomness on the blockchainRISC seminars, CWI Cryptology Group, Amsterdam, The Netherlands (September 2016) · slides
65. Trust, and public entropy: a unicorn huntNIST Workshop on Random Bit Generation, Gaithersburg, MD, USA (May 2016) · slides
66. A random zoo: sloth, unicorn and trxALMASTY seminars, Université Pierre et Marie Curie, Paris, France (December 2015) · slides (french)
67. A random zoo: sloth, unicorn and trxJournées Codage et Cryptographie, La Londe-les-Maures, France (October 2015)
68. A random zoo: sloth, unicorn and trxNIST Workshop on Elliptic Curve Cryptography Standards, Gaithersburg, MD, USA (June 2015) · slides
69. Random self-reducibility of the discrete logarithm problem in genus 2LACAL@RISC Seminar on Cryptologic Algorithms, CWI Amsterdam, The Netherlands (February 2015) · slides