CATREL Workshop: Advances in Discrete Logarithms

GRACE will host a workshop on advances in finite field discrete logarithms on October 1 and 2, 2015. This is the closing event for the CATREL project, where we will celebrate the massive advances in the DLP over the last three years, while looking forward to the future.

Thursday 1/10

9h30-10h00: Welcome/Coffee
10h00-10h05: Opening
10h05-10h50: Rob Granger
On the interplay between theory and practice in small characteristic DLPs (slides)
10h50-11h35: Thorsten Kleinjung
On degree-two elimination
11h35-12h20: Steven Galbraith
Open problems in applications of Fourier learning to the Diffie-Hellman problem in finite fields (slides)
12h20-13h30: Lunch
13h30-14h15: Gora Adj
Discrete logarithms in small characteristic finite fields:
Attacking Type 1 pairing-based cryptography
14h15-15h00: Claus Fieker
Problems and approaches in class groups of large degree fields (slides)
15h00-15h30: Coffee
15h30-16h15: Karthik Bhargavan
Imperfect Forward Secrecy: How Diffie-Hellman Fails in Practice (slides)
16h15-17h00: Dale Sibborn
Cold Boot Attacks in the Discrete Logarithm Setting (slides)

Friday 2/10

9h30-10h15: Pierrick Gaudry
The CADO-NFS software (slides)
10h15-11h00: Andrea Miele
Post-sieving on GPUs (slides)
11h00-11h30: Coffee
11h30-12h15: Cyril Bouvier
The filtering step of discrete logarithm and integer factorization algorithms (slides)
12h15-13h00: Emmanuel Thomé
Block Wiedemann likes Schirokauer Maps (slides)
13h00-14h00: Lunch
14h00-14h45: Aurore Guillevic
Faster individual logarithms in GF(p^n) (slides)
14h45-15h30: Antoine Joux
Squirrels and toothbrushes
15h30-16h15: Razvan Barbulescu
How to get rid of units (slides)

Details and registration
The workshop will take place on the École polytechnique campus in Palaiseau, France (in the southern suburbs of Paris).

The workshop is free of charge, but registration will be necessary for organisational reasons.
You can register here.

ECC Bordeaux
This workshop immediately follows the Elliptic Curve Cryptography conference in Bordeaux.

CATREL project meeting

On january 13 and 14, Grace hosts fifteen participants for a CATREL (ANR project) meeting.

The schedule:


  • 14h15. A. Guillevic : Polynomial selection for GF(p^k)
  • 15h00. J. Detrey : Smithcopper
  • 15h30. P. Gaudry : Comparaison de cado-nfs et des implémenations
    mpqs (10 minutes) (mais où est donc le cross-over de nos jours?)

  • 16h30. M. Massierer : Is there an L(1/4) algorithm for the discrete logarithm problem in algebraic curves?
  • 17h15. Business meeting


  • 10h00. P. Gaudry : Le hardware c'est triché!
  • 11h15. P. Zimmermann : Tiny MPQS (30 ou 45 min)
  • 11h15. F. Morain : The theory around SQUFOF

October 2014: new arrivals

  • Johan Nielsen, two years Digiteo postdoc, working with Luca de Feo on a general, Coppersmith-like, framework for Sudan's list decoding
  • David Lucas, starting engineer, will work on the Sage framework for coding theory
  • Virgile Ducet, polytechnique postdoc, will work on the weight distribution of AG codes

Sciences en Marche

GRACE supports Sciences en Marche.

Our local seminar (Groupe de Travail)

    Year 2105.

  • December, 15th, 13h30, Aurore Guillevic (Grace) Computing Discrete Logarithms in GF(p^k )
  • December, 15th, 15h00, François Morain (Grace) Factorisation d'entiers -- hier, aujourd'hui, demain

    De tous temps, il y a eu des passionnés des nombres pour
    factoriser des entiers. De nos jours, c'est devenu un enjeu de
    sécurité. Les techniques ont évolué avec le temps, le matériel
    également. Après un bref survol du passé et du présent, nous
    présenterons l'algorithme de factorisation de Shor, qui fonctionne

Discrete logarithm postdocs

We're currently looking for a postdoc to work on discrete logarithms as part of the CATREL ANR project. We have a two-year position on offer (starting no later than January 1, 2014); our colleagues in team CARAMEL are offering a second two-year job starting in September, 2014.

For information on both positions, see
For the official posting for the job with us at LIX, see
Feel free to contact us with any questions!

Workshop on Number-Theoretic Algorithms for Asymmetric Cryptology

With the support of the Labex DigiCosme, team GRACE hosted an international workshop on Number-Theoretic Algorithms for Asymmetric Cryptology on the 20th and 21st of June, 2013.


Razvan Barbulescu (LORIA)
A quasi-polynomial algorithm for discrete logarithms in finite fields of small characteristic. Slides / Preprint / Ellipticnews blog writeup
Andreas Enge (INRIA Bordeaux–Sud-Ouest)
Class Polynomials for Abelian Surfaces. Slides / Preprint
Steven Galbraith (Auckland)
Computational problems and lattices, and public key signatures. Slides (pdf)
Florian Hess (Oldenburg)
Pairing inversion, and towers of curves. Slides (pdf)
Antoine Joux (Cryptoexperts and UVSQ)
Discrete logarithms in small characteristic finite fields: An L(1/4+o(1)) algorithm. Slides / Preprint
Vadim Lyubashevsky (INRIA Paris–Rocquencourt and ENS Paris)
Lattice signatures and bimodal gaussians. Slides / Preprint
Ben Smith (INRIA Saclay–Île-de-France and École polytechnique)
Q-curves and faster Elliptic Curve Diffie-Hellman key exchange. Slides / Preprint

Daniel Augot, Shi Bai, Jean-Claude Bajard, Razvan Barbulescu, Peter Birkner, Cyril Bouvier, John Boxall, Svyatoslav Covanov, Luca De Feo, Cyril Hugounenq, Nicolas Delfosse, Iwan Duursma, Andreas Enge, Jean-Pierre Flori, Georg Fuchsbauer, Steven Galbraith, Cécile Gonçalves, Eleonora Guerrini, Aurore Guillevic, Florian Hess, Laurent Imbert, Sorina Ionica, Hamza Jeljeli, Antoine Joux, Alexander Kruppa, Fabien Laguillaumie, Tancrède Lepoint, Vadim Lyubashevsky, François Morain, Olivier Orcière, Matthias Peter, Cécile Pierrot, Julia Pieltant, Thomas Plantard, Thomas Prest, Guenael Renault, Benjamin Smith, Emmanuel Thomé, Bastien Vialla.

New Directions

We've added a helpful new guide to visiting LIX:

Two new masters internships available

GRACE is now offering two new masters-level internships: see our Jobs page.

News: January 2013

New building; Welcome Nicolas Delfosse and Julia Pieltant; Jérôme Milan departs; ANR Catrel

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