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Secure Communications over Arbitrarily Varying Wiretap Channels

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posted on 2009-12-11, 00:00 authored by Ebrahim MolavianJazi
In this thesis, we consider a class of information protection problems requiring confidentiality (secrecy) from eavesdropping and integrity (reliability) from jamming in an information-theoretic context. For this purpose, we introduce the arbitrarily varying wire-tap channel (AVWTC) model consisting of a family of wiretap channels indexed by some state that is selected by the jammer in an arbitrary and time-varying manner. We study this model for traditional wiretap codes and randomized wiretap codes, and develop insights about the corresponding secrecy capacity and randomized-code secrecy capacity, respectively. We characterize a lower bound on the randomized-code secrecy capacity of the AVWTC that suggests the secrecy is mainly dictated by a worst-case scenario. Additionally, we establish two upper bounds on the randomized-code secrecy capacity that suggest a single bad ``averaged' state can preclude secure communication, while certain superiorities of the legitimate receiver over the eavesdropper in all ``averaged' states result in a positive secrecy capacity. Finally, we prove that the secrecy capacity of the AVWTC is either zero or equal to its randomized-code secrecy capacity. We show that a ``two-layer' wiretap code is appropriate for combatting the two non-colluding jamming and eavesdropping adversaries.

History

Date Modified

2017-06-05

Research Director(s)

J. Nicholas Laneman

Committee Members

Matthieu Bloch Thomas Fuja

Degree

  • Master of Science in Electrical Engineering

Degree Level

  • Master's Thesis

Language

  • English

Alternate Identifier

etd-12112009-112419

Publisher

University of Notre Dame

Additional Groups

  • Electrical Engineering

Program Name

  • Electrical Engineering

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