Missions

The aim of this project is to investigate the use of wiretap coding in highly directive links and to obtain new bounds for the finite-blocklength secrecy rate under a mutual information secrecy constraint.

Activities

Context :
Physical layer security techniques are being envisaged for future 6G networks [1,2] as a first line
of defense with low latency and low computational cost. A key requirement for their practical implementation is the guarantee of an asymmetry in the signal quality between legitimate terminals and attackers. New technologies, such as sharp beamforming using massive MIMO as well as distributed MIMO, channel engineering using Reconfigurable Intelligent Surfaces, as well as transmission in the mmWave / THz range with high directivity for short range scenarios, could provide such security advantages, allowing in particular to make the case for wiretap coding.
The potential use cases for wiretap codes include Internet of things (IoT) networks featuring short packet payloads, and ultra-reliable low latency communications (URLLC).
Research program :
For applications requiring short packets / low latency, it is important to obtain tight bounds for the optimal secrecy rate in finite blocklength.
Building on the theoretical breakthrough by Polyanskiy, Poor and Verdù in the analysis of finite-length channel coding rates [3], Yang, Schaefer and Poor [4] proved tight bounds on the second-order coding rate for discrete memoryless and Gaussian wiretap channels. In this work, the information leakage is measured in terms of total variation distance between the joint distribution of the secret message M and the eavesdropper's observation Z, and an ideal distribution in which M is uniformly distributed and independent of Z.
However, for many applications it is preferable to measure confidentiality in terms of information leakage, i.e. of mutual information between M and Z.
The project will focus on establishing new bounds for the secrecy rate under a mutual information constraint for discrete memoryless wiretap channels and Gaussian wiretap channels.

[1] L. Mucchi, S. Jayousi, S. Caputo, E. Panayirci, S. Shahabuddin, J. Bechtold, I. Morales, R.-A. Stoica, G. Abreu, and H. Haas, “Physical-layer security in 6G networks,” IEEE Open Journal of the Communications Society, vol. 2, pp. 1901–1914, 2021.
[2] A. Chorti, A. N. Barreto, S. Köpsell, M. Zoli, M. Chafii, P. Sehier, G. Fettweis, and H. V. Poor, “Context-aware security for 6G wireless: The role of physical layer security,” IEEE Communications Standards Magazine, vol. 6, no. 1, pp. 102–108, 2022.
[3] Y. Polyanskiy, H. V. Poor, and S. Verdú, “Channel coding rate in the finite blocklength regime,” IEEE Transactions on Information Theory, vol. 56, no. 5, p. 2307, 2010.
[4] W. Yang, R. F. Schaefer, and H. V. Poor, “Wiretap channels: Nonasymptotic fundamental limits,” IEEE Transactions on Information Theory, vol. 65, no. 7, pp. 4069–4093, 2019.

Skills

Requirements
For this position, you should meet the following requirements:
• PhD in information theory
• Expertise in physical layer security and finite-blocklength communications
• Proficiency in spoken and written English
• Scientific curiosity and desire to work in an interdisciplinary project
• Intellectual rigor and proactive attitude

Hiring process
All applications must be submitted via this portal (i.e. Portail emploi CNRS) by ****
and should include:
• CV (3 pages max)
• Motivation letter including a short description of your background, a statement of your
research interests and motivation for this position, and why you think you would be a good
fit (1 page)
• Summary of the PhD research
• Two reference letters or contact details of two referees
• Two samples of publications (links to publicly available online documents are accepted)
For full consideration, all the items listed above should be included or the absence thereof justified.

Work Context

This position is funded by the PEPR 5G Networks of the Future project, PC8 NF-HiSec « End-to-End Security for the network of the future ». The project is thus part of a larger scientific project including internal and external collaborations from which the candidate will be able to benefit. The project will be carried out in the ICI (Information, Communication, Imagerie) team of ETIS (UMR8051), under Dr. Laura Luzzi's primary supervision and in collaboration with Pr. Arsenia Chorti.
ETIS is a joint lab between CY Cergy Paris Université, ENSEA and CNRS, and a prominent
research unit in computer science and information technologies in France. ICI is one of ETIS's
four multi-PI groups and is specialized in signal processing, information theory and wireless communications. The group's research areas include optimization of resource allocation for wireless communication systems, massive MIMO, NOMA systems, physical layer security, etc.
ICI has built a world-class reputation and has become a major actor in these research
areas in France with multiple national and international collaborations.

The position is located in a sector under the protection of scientific and technical potential (PPST), and therefore requires, in accordance with the regulations, that your arrival is authorized by the competent authority of the MESR.