Andrea Lesavourey

Research   Teaching   Contact

I am currently a post-doctoral researcher at Univ Rennes, CNRS, IRISA, working within the CAPSULE team under the supervision of Adeline Roux-Langlois. Previously, I was a Ph.D. student at University of Wollongong, Australia under the supervision of Willy Susilo and Thomas Plantard.

Here is my (french) CV.



I am currently working on lattice-based cryptography with a focus on algebraic lattices and their underlying number theoretical structure. More generally, I am interested by computer algebra, algebraic number theory and their applications to cryptography.

PhD thesis

My Ph.D. thesis can be found here.
Please, feel free to contact me if you have any question, remark or if you spot any error/typo.


  1. Computing roots of polynomials over number fields using complex embeddings, Willy Susilo and Thomas Plantard.
    Code available here

  2. On the Short Principal Ideal Problem over some real Kummer fields, with Willy Susilo and Thomas Plantard.
    Code available here

  3. A note on the discriminant and prime ramification of some real Kummer extensions.

Journal Papers

  1. Short Principal Ideal Problem in multicubic fields, Journal of Mathematical Cryptology, 14(1), 359-392, with Willy Susilo and Thomas Plantard
    Journal version of the paper below, presented at NutMic 2019.

Conference Papers

  1. Log-S-unit lattices using Explicit Stickelberger Generators to solve Approx Ideal-SVP, with Olivier Bernard, Tuong-Huy Nguyen, and Adeline Roux-Langlois.
    ASIACRYPT 2022.
    Code available here

  2. Covering Radius and First Minima Bound on Diagonally Dominant Lattices in the l$_\infty$-norm, with Thomas Plantard and Arnaud Sipasseuth.
    Number-Theoretic Methods in Cryptology (Nutmic) 2021.

  3. On ideal lattices in multicubic fields, with Willy Susilo and Thomas Plantard.
    Number-Theoretic Methods in Cryptology 2019

  4. Efficient Leak Resistant Modular Exponentiation in RNS, with C. Negre and T. Plantard.
    Proceedings of ARITH 24. 24th IEEE Symposium on Computer Arithmetic. London, England, July 24-26, 2017, pages 156-163.

  5. Efficient Randomized Regular Modular Exponentiation using Combined Montgomery and Barrett Multiplications, with C. Negre and T. Plantard.
    SECRYPT 2016. The 13th International Conference on Security and Cryptography. Lisbon, Portugal, July 26-28, 2016, pages 368-375.

Presentations and talks

Summer schools and workshops

  1. Structured Matrix Days, 2022
    Covering radius and first minimum of diagonally dominant lattices for the max norm

  2. Journées Codages et Cryptographie, 2022
    Calcul de racines de polynômes dans un corps de nombres

  3. Journées Codages et Cryptographie, 2020
    Retrieving short generators of principal ideals in real Kummer extensions.

  4. School for young reaserchers by the GDR-IM in France
    Retrouver des générateurs courts d'idéaux principaux dans certaines extensions de Kummer réelles


  1. Séminaire Cryptologie & Sécurité, GREYC, Caen (2022)
    Vecteurs courts dans des réseaux idéaux ; études pratiques.

  2. Séminaire de l'équipe CASC, Laboratoire Jean Kuntzmann, Grenoble (2022)
    Vecteurs courts dans des réseaux idéaux ; étude pratique et calculs efficaces

  3. Séminaire de l'équipe Calcul Formel, XLIM, Limoges (2022)
    Vecteurs courts dans des réseaux idéaux ; étude pratique et calculs efficaces



I helped organise and took part to the First Workshop On Mathematics and Algorithms for Cryptographic Advanced Objects, MACAO.

Editorial work

I have been a sub-reviewer for the conference ACISP 2020 and 2022.


First semester 2022-2023

Second semester 2021-2022

First semester 2021-2022

Autumn Session 2020 and 2021

Autumn Session 2019


Andrea Lesavourey