On March 27 and 28 at CALM (Campus la Borie, Limoges) the “Cordées de la Recherche” (Research climbing rope) workshops will take place. The opportunity for our M1 students to present their scientific work in poster form.

The two days will be punctuated by conferences.

For this 2025 edition, discover each week the portraits of the speakers who will be present.

The portrait of the week is Pr. Nicolas Aragon:

Abstract:

Post-Quantum Cryptography

Cryptography is everywhere: from secure messaging apps, to payment solutions or even browsing the Internet, we use it everyday without even noticing it. It allows us to exchange information privately, and to ensure that the companies/websites we are consulting are indeed who they claim to be.

To build cryptographic protocols, we need to rely on hard mathematical problems. Nowadays, most systems we use are based on either the factoring of large integers, or the discrete logarithm problem.

But cryptography is facing a new challenge: large investments are currently being used to develop quantum computers. These computers, capable of leveraging quantum physics to run new algorithms, are very well suited to solve both the factoring and discrete logarithm problems. This is know since the invention of the Shor algorithm in 1994, but was not considered a menace before quantum computers started improving really quickly these past few years.

This talk will present the field of Post-Quantum Cryptography (PQC): what are the new mathematical problems being used to develop modern cryptosystems, what is the state of these developments, and how we are involved in this transition process at Xlim.

Bio :

My main research interest is designing and studying the security of post-quantum cryptosystems, with a focus on code-based cryptography. I am interested in the development of cryptographic software, trying to improve both the performance and the security of cryptographic implementations.
I am currently an Associate Professor at Université de Limoges, and I work in the Cryptis team of the Xlim research laboraory. Previously, I was a postdoctoral researcher in the CAPSULE team at IRISA, in Rennes. I defended my PhD thesis, “Cryptography based on rank metric error correcting codes and applications”, in 2020, under the supervision of Philippe Gaborit and Gilles Zémor.