Soutenance de Thèse de Doctorat en "Telecommunications and Mobile Networks" par Mr. Flavien DONKENG ZEMO
CEDOC
The Euromed University of Fes (UEMF) is pleased to inform the public of
the doctoral thesis defense in ” Telecommunications and Mobile Networks”
The thesis defense will take place on Monday, July 14, 2025, at 09:00 a.m.at l’UEMF
Location: Gallery, Building 1
The thesis will be presented by Mr. Flavien DONKENG ZEMO
under the theme :
“ SECURITY THREATS AND DEFENSE STRATEGIES FOR COOPERATIVE SPECTRUM SENSING IN 6G COGNITIVE RADIO NETWORKS ”
Summary
The exponential growth of connected IoT devices driven by applications like remote surgery, smart cities, and autonomous vehicles demands next-generation wireless capabilities. While 6G networks promise ultra-high performance, they must overcome critical challenges in spectral efficiency and physical-layer security to support ultra-massive IoT deployments. Current static spectrum allocation exacerbates scarcity, with studies revealing utilization rates as low as 15-85%. Cognitive Radio Networks (CRNs) address this by enabling secondary users (SUs) to dynamically access underutilized licensed bands without disrupting primary users (PUs), though their effectiveness hinges on reliable spectrum sensing.
Cooperative Spectrum Sensing (CSS) mitigates limitations like hidden-node problems by leveraging collaborative sensing among multiple SUs. However, CSS systems are vulnerable to physical-layer attacks, particularly Spectrum Sensing Data Falsification (SSDF) attacks, where malicious SUs falsify sensing reports to blind the Fusion Center (FC). This research confronts massive independent SSDF attacks in centralized CSS. We first propose a probabilistic SSDF attack model enabling adaptable, stealthy adversarial strategies. The blind FC problem is then formalized to characterize defense requirements.
Two novel defense mechanisms are developed: The first combines reputation-based Byzantine identification with a sequential weighted fusion scheme, enabling rapid, accurate decisions using minimal samples. The second employs an enhanced reputation method paired with weighted majority fusion for robustness against random SSDF attacks. Extensive MATLAB simulations confirm both mechanisms outperform existing solutions, maintaining detection accuracy even when attackers comprise 90% of SUs across diverse attack strategies.
Keywords: Cognitive Radio Networks, Cooperative spectrum sensing, Spectrum Sensing Data Falsification attack, Primary User Emulation attack.
This thesis will be presented to the jury members:
| Full name | Grade | Institution | Quality |
|---|---|---|---|
| Prof. Abdelghafour MARFAK | PES | Euromed University of Fes | Jury Chair |
| Prof. Farid ABDI | PES | FST, Sidi Mohamed Ben Abdellah University of Fes | Reviewer |
| Prof. Mohamed EL GHAZI | PES | EST, Sidi Mohamed Ben Abdellah University of Fes | Reviewer |
| Prof. Mohammed BENBRAHIM | PES | FSDM, Sidi Mohamed Ben Abdellah University of Fes | Reviewer |
| Prof. Kaouthar CHETIOUI | PH | ENSA, Sidi Mohamed Ben Abdellah University of Fes | Examiner |
| Prof. Fatiha MRABTI | PES | FST, Sidi Mohamed Ben Abdellah University of Fes | Examiner |
| Prof. Ahmed El Hilali ALAOUI | PES | Euromed University of Fes | Thesis Director |
| Prof. Sara BAKKALI | PA | Euromed University of Fes | Thesis co-Director |
