International collaborations
Spring 2018
I enjoyed several fruitful visits to David Kohel in Luminy, Tanja Lange's group in Eindhoven, as well as KULeuven. Watch out for forthcoming publications!
Summer 2017
I had a great time visiting Kristin Lauter at Microsoft Research Redmond; check out my talk on isogeny-based crypto there.
Finally made a paper from our 6-year old draft on supersingular isogeny problems!
Summer 2016
Always a pleasure to visit Paris, this time to work on root-finding algorithms with Luca de Feo and Michael Quisquater.
Spring 2016
I had great and productive time in New Zealand, invited by Steven Galbraith. Look for our joint publications to come!
December 2015
I had great time in Singapour visiting Sze Ling Yeo. We haven't broken ECDLP yet, but we are still working on it!
Spring 2015
I had an excellent time at AIMS-Senegal teaching a course on Cryptography (in mission for the International Mathematical Union) and meeting with my PhD student Ange-Salome Messeng Ekossono.
Summer 2014
I made a short invited visit to Beijing University for Post and Telecomunications to work on non-Abelian cryptography.
2013-2014
Visit to Jens Groth, Computer Science Department, University College London.
2013-2014
Visit to Alan Lauder, Number Theory Group, University of Oxford.
Summer 2013
I again visited Prof. Tsuyoshi Takagi at Kyushu University, Fukuoka, Japan.
We worked on improving my previous work on binary ECDLP from Eurocrypt 2012 and Asiacrypt 2012.
This visit led to another joint paper currenty under review.
Spring 2013
I was back to Kinshasa, RD Congo, in mission for the International Mathematical Union, to give a course on Computer Security and Cryptography at Unikin.
Winter 2013
I visited Prof. Tsuyoshi Takagi at Kyushu University, Fukuoka, Japan.
We worked on improving my previous work on binary ECDLP from Eurocrypt 2012 and Asiacrypt 2012.
This visit led to this publication, which was granted the best student paper.
Summer 2012
I spent one week in June teaching on Computer Security and Cryptography at the Faculté polytechnique de l'Unikin, Kinshasa, RD Congo.
Many thanks to Prof. Sam Yala, Prof. Jean-Marie Moanda and Prof. Gildas Avoine who helped make this possible.
Spring 2012
From February to April, I had great time at the Laboratoire d'informatique de l'Ecole Polytechnique (LIX), Paris, France, headed by Daniel Augot.
Fall 2011
From September to December, I made a third visit to Kristin Lauter (Microsoft Research) in San Diego.
I was hosted at the Computer Science Department of UCSD by Professor Daniele Micciancio.
With Kristin Lauter, we continued our cryptanalysis work on the Pizer hash function. Part of this work has now been published in the LMS Journal of Mathematics for ANTS 2014.
Summer 2011
From mid-July to mid-August, I spent another month at LIP6 (UPMC), within Jean-Charles Faugère's group.
Follow-up of my previous visit.
These two short visits lead to two publications available here and here.
Winter 2011
From January to February I visited Jean-Charles Faugère (directeur de recherches INRIA-UPMC),
Ludovic Perret (UPMC) and Guénaël Renault (UPMC) in Paris.
Factorization problem in the group SL(2,2^n) and on the elliptic curve discrete logarithm problems over finite fields of characteristic 2.
Spring 2010
From February to May I visited Kristin Lauter (Microsoft Research) in San Diego.
I was hosted at the Computer Science Department of UCSD by Professor Daniele Micciancio.
With Kristin Lauter, we worked on the Pizer hash function , constructed from graphs of isogenies between supersingular elliptic curves. I learned p-adic analysis, quaternion algebras and their link to the endomorphism ring of supersingular elliptic curves and to their graphs of isogenies.
We tried some approach to cryptanalyse the function (still work in progress).
Spring 2008
From February to May I visited Kristin Lauter (Microsoft Research) in San Diego.
I was hosted at the Computer Science Department of UCSD by Professor Daniele Micciancio.
With Kristin Lauter and Jean-Jacques Quisquater (UCL), we worked on the LPS hash function constructed from the famous Lubotzky-Philips-Sarnak's Ramanujan graphs. We found very efficient preimage algorithms, therefore completing the cryptanalysis of the function. We also broke the Morgenstern hash function at the same time.
This work was presented at the Sixth Conference on Security and Cryptography for Networks . The paper is available here.
Other collaborations
With Gilles Zémor (professeur at Bordeaux I), Jean-Pierre Tillich (INRIA Rocquencourt) and Jean-Jacques Quisquater (UCL) we found generic attacks on cryptographic hash functions constructed from the graph of SL(2,2^n), and we proposed new constructions.
This work was presented at the Cryptographers' track of the RSA Conference 2009. The paper is available here.
With François-Xavier Standaert (UCL), Olivier Pereira (UCL), Tal Malkin (Columbia university) and Moti Young (Google and Columbia university), we designed a new pseudo random number generator with enhanced resistance against side-chanel attacks.
This work was presented at the ACM Symposium on Information, Computer and Communications Security in 2008. The paper is available here.