7th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks

Research Article

Physical Layer Security: Coalitional Games for Distributed Cooperation

  • @INPROCEEDINGS{10.1109/WIOPT.2009.5291619,
        author={Walid Saad and Zhu Han and Tamer Başar and Merouane Debbah and Are Hjorungnes},
        title={Physical Layer Security: Coalitional Games for Distributed Cooperation},
        proceedings={7th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks},
        publisher={IEEE},
        proceedings_a={WIOPT},
        year={2009},
        month={10},
        keywords={physical layer security coalitional games game theory coalition formation},
        doi={10.1109/WIOPT.2009.5291619}
    }
    
  • Walid Saad
    Zhu Han
    Tamer Başar
    Merouane Debbah
    Are Hjorungnes
    Year: 2009
    Physical Layer Security: Coalitional Games for Distributed Cooperation
    WIOPT
    IEEE
    DOI: 10.1109/WIOPT.2009.5291619
Walid Saad1,*, Zhu Han2,*, Tamer Başar3,*, Merouane Debbah4,*, Are Hjorungnes1,*
  • 1: UNIK - University Graduate Center, University of Oslo, Norway,
  • 2: Electrical and Computer Engineering Department, University of Houston, USA
  • 3: Coordinated Science Laboratory, University of Illinois at Urbana-Champaign, USA
  • 4: Alcatel-Lucent Chair on Flexible Radio, SUP´ ELEC, Gif-sur-Yvette, France
*Contact email: saad@unik.no, zhan2@mail.uh.edu, basar1@illinois.edu, merouane.debbah@supelec.fr, arehj@unik.no

Abstract

Cooperation between wireless network nodes is a promising technique for improving the physical layer security of wireless transmission, in terms of secrecy capacity, in the presence of multiple eavesdroppers. While existing physical layer security literature answered the question “what are the link-level secrecy capacity gains from cooperation?”, this paper attempts to answer the question of “how to achieve those gains in a practical decentralized wireless network and in the presence of a secrecy capacity cost for information exchange?”. For this purpose, we model the physical layer security cooperation problem as a coalitional game with non-transferable utility and propose a distributed algorithm for coalition formation. Through the proposed algorithm, the wireless users can autonomously cooperate and self-organize into disjoint independent coalitions, while maximizing their secrecy capacity taking into account the security costs during information exchange. We analyze the resulting coalitional structures, discuss their properties, and study how the users can self-adapt the network topology to environmental changes such as mobility. Simulation results show that the proposed algorithm allows the users to cooperate and self-organize while improving the average secrecy capacity per user up to 25.32% relative to the non-cooperative case.