Security and Trust for Wireless Autonomic Networks

We analyze and solve various problems of security, information assurance and trust in dynamic wireless networks. These include detection and defense against attacks, detection of propagating viruses, evaluation of intrusion systems, attacks at the physical, MAC and routing protocols, trust establishment-dynamicsmanagement. We demonstrate persistently that systems and control models and methodologies provide new and powerful techniques to analyze these problems. We describe the use of distributed change detection methods and algorithms for intrusion detection and the use of non-cooperative games for the detection and defense against attacks at all layers. We demonstrate how Bayesian decision theory can be used to evaluate intrusion detection systems and we resolve some key problems in this area. We use game theoretic methods again to develop robust protocols against attacks, including Byzantine ones. We provide an in-depth investigation of trust establishment and computation in such networks. We describe various methods for distributed trust evaluation and the associated trust (and mistrust) ‘spreading’ dynamics. We investigate rules and policies that establish ‘trust-connected’ networks using only local interactions, and find the parameters (e.g. topology type) that speed up or slow down this transition. We describe and explain the phase transition phenomena that we have found in these evolutions. We model the interactions among agents as cooperative games and show that trust can encourage agents to collaborate. This leads us to a fundamental analytical technique, constrained coalitional games, that can be used to evaluate tradeoffs in collaborative networks in various areas: communications, sensors, economics, sociology, biology. We also describe a model for trust evaluation that uses pairwise iterated graph games between the agents to create a ‘trust reputation’ with evolution coupled to the game dynamics. Finally we present a new modeling framework for trust metric evaluation as linear iterations over ordered semirings. This allows us to formulate problems of resilience of trust metrics and trust evaluation to attacks.