Description du sujet de thèse

Hybrid solutions are being considered for the transition for post-quantum cryptography, resistant to quantum computers. These solutions should allow the support of both well established solutions (e.g., RSA, ECC) and post-quantum ones that are still in the study and standardization phase. Thus flexible hardware accelerators must be designed to support hybrid solutions. In addition to flexibility on the types of cryptosystems, accelerators must also offer different levels of security by supporting multiple key sizes and different combinations of protections against physical attacks by observation or perturbation.

The thesis will focus on the study, FPGA implementation, validation and evaluation of agile hardware accelerators that are secure against physical attacks by observation or perturbation. We will start by studying the state of the art of pre- and post-quantum solutions and their hardware implementations; physical attacks and associated protections. In parallel to the study of the state of the art, the recruited person will complete his/her training (see profiles below). We will identify and select cryptographic algorithms that can be combined (e.g., ECC and isogenies between curves); hardware acceleration solutions; and protections to combine them in an agile and secure accelerator. It will be necessary to be
comfortable with different cryptographic algorithms and their mathematical operations in order to combine them in FPGA in an agile and secure accelerator. One research direction that we are considering is the use of modular number representation (RNS) to combine recognized ECC solutions and post-quantum
solutions based on isogenies solutions studied in another project. We wish to study in detail the possibilities offered by RNS to randomize calculations and detect faults. For each solution, existing or new, we will study its theoretical aspects, we will evaluate its usability and flexibility, we will perform high level simulations and implement it on FPGA. We will perform intensive functional validations and comparisons in simulation and on FPGA board simulation and on FPGA board, and finally we will proceed to security evaluations against
physical attacks.

Profile for candidates:

This multidisciplinary thesis requires very good knowledge in several of the following areas:

- asymmetric cryptography (ECC, RSA, euclidean networks, isogenies)
- design of FPGA architectures in Verilog or VHDL
- finite field arithmetic
- Python and C programming
- writing, synthesis and analysis of documents
- oral presentation and collaborative work

Typical candidates profiles:

- Master's degree or engineering degree in cryptography with very good knowledge of C and Python programming. The hired person will be trained in FPGA design aspects. This profile being particularly rare in the industry and the government services, this thesis will provide very good opportunities for the person recruited.
- Master's degree or engineering degree in embedded computing or digital electronics with very good knowledge in arithmetic and at least a good basis in cryptography. The hired person will be trained in the implementation of cryptosystems.

Contexte de travail

The recruited person will be employed at the CNRS on a 3-year fixed-term contract (CDD) in the laboratory Lab-STICC UMR6285 (https://labsticc.fr/) on the site of ENSTA Bretagne (https://www.ensta-bretagne.fr/) in Brest and will be enrolled in a thesis in the SPIN Doctoral School (https://ed-spin.doctorat-bretagne.fr/).

The thesis will take place in the ARSENE project (https://www.pepr-cybersecurite.fr/projet/arsene/) of the PEPR Cybersecurity which gathers the French teams in this field.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Informations complémentaires

Applications must be submitted on the CNRS portal (file in PDF format) and must include:
- a CV detailing the knowledge and experience in the themes of the subject;
- a cover letter indicating your motivation and interest for this position and subject;
- detailed transcripts from the different years of your bachelor's/master's degree or engineering degree;
- the complete contact details and functions of 2 reference persons (e.g. internship or training supervisor) whom we will contact directly.

Applications will be reviewed on a rolling basis until the position is filled. The starting date of the contract, expected in October 2023, may be slightly flexible.

If you have any questions, please contact A. Tisserand: arnaud.tisserand@cnrs.fr