The ability to transfer information securely, to guarantee privacy, and to authenticate users in wireless networks forms the basis for confidentiality and economic advantage in today's information society. Contemporary wireless security systems evolved from schemes developed for traditional wireline applications, ignoring the special features of radio propagation channels. Meanwhile, the secrecy of wireless networks can be strengthened by exploiting the physical properties of these radio channels. Current research activities in this direction have largely ignored radio interference that can affect the secrecy of communication in a fundamental way. Therefore, it is crucial to characterize the various effects of interference (conventionally considered deleterious for communications) on network secrecy, as well as to develop techniques that exploit intrinsic properties of interference and radio channels for improving network secrecy.
This research establishes foundations for the intrinsically secure exchange of information within wireless communities formed by spatially distributed legitimate users, interferers, and eavesdroppers. Principles and concepts from multiple disciplines such as communication theory, information theory, statistical inference, probability theory, stochastic geometry, and graph theory are employed to characterize the role of interference on network secrecy. In particular, this research (1) establishes a framework to determine the secrecy rate in large-scale wireless networks; (2) determines the properties of the iSI-graph, a random geometric graph that characterizes intrinsic secrecy in the presence of interference; (3) analyzes network secrecy in the presence of colluding eavesdroppers; and (4) evaluates the performance of secrecy enhancing techniques, including deliberate interference generation and sectorized transmission. This research provides a deeper understanding of the advantages and disadvantages of interference on network secrecy, paving the way to a more secure and safer information society.