Post doc M/F : Fundamental limits of wiretap channels in finite-blocklength

CNRS; France; Sur place; EUR 40 000 - 60 000; Plein temps

Résumé du poste

A leading research organization in France seeks a researcher to investigate wiretap coding in the context of physical layer security, especially for future 6G networks. The role entails establishing new bounds for secrecy rates and requires a PhD in information theory. Ideal candidates will have expertise in physical layer security and finite-blocklength communications, along with proficiency in English. The position offers full-time hours and involvement in collaborative research projects.

Qualifications

• Candidates must hold a PhD in information theory.
• Expertise in physical layer security and finite-blocklength communications is essential.
• Proficient in both spoken and written English.

Responsabilités

• Investigate wiretap coding for highly directive links.
• Establish new bounds for the secrecy rate under a mutual information constraint.
• Collaborate on interdisciplinary projects within an established research team.

Connaissances

Expertise in physical layer security

Proficiency in spoken and written English

Scientific curiosity

Intellectual rigor

Proactive attitude

Formation

PhD in information theory

Description du poste

Organisation/Company CNRS Department Equipes Traitement de l'Information et Systèmes Research Field Engineering Computer science Mathematics Researcher Profile Recognised Researcher (R2) Country France Application Deadline 1 Jan 2026 - 23:59 (UTC) Type of Contract Temporary Job Status Full-time Hours Per Week 35 Offer Starting Date 1 Mar 2026 Is the job funded through the EU Research Framework Programme? Not funded by a EU programme Is the Job related to staff position within a Research Infrastructure? No

Offer Description

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.

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.

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.

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 ****

• 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.