Opportunistic networks provide an ad hoc communication medium without the need for an infrastructure network, by leveraging human encounters and mobile devices. Routing protocols in opportunistic networks frequently rely upon encounter histories to build up meaningful data to use for informed routing decisions. This seminar presents work showing it is possible to use pre-existing social-network information to improve existing opportunistic routing protocols, and that these self-reported social networks have a particular benefit when used to bootstrap an opportunistic routing protocol.

Frequently, opportunistic routing protocols require users to relay messages on behalf of one another: an act that incurs a cost to the relaying node. Nodes may wish to avoid this forwarding cost by not relaying messages. Opportunistic networks need to incentivise participation and discourage the selfish behaviour. This seminar further presents an incentive mechanism that uses self-reported social networks to construct and maintain reputation and trust relationships between participants, and demonstrates its superior performance over existing incentive mechanisms.

Greg Bigwood is a Ph.D. student in the School of Computer Science at the University of St Andrews. He works in the field of opportunistic networks and social networks, researching the use of social-network information to improve opportunistic networks.

He read Computer Science at the University of St Andrews, graduating in 2007.

Abstract: I describe a mathematical systems modelling framework that is motivated by a desire to represent and reason about properties of (large-scale) systems situated in dynamic environments. Motivated by the concepts of distributed systems theory, the framework has at its core mathematical treatments of environment, location, resource, and process, and comes along with a separating modal logic. Extensions to analyze questions in computer security are also considered. The mathematical structures provide a semantics for a modelling tool, called (Core) Gnosis, that, together with some elementary utility theory, has been deployed in a range of commercial projects undertaken with Hewlett-Packard’s information security business and its customers. I conclude by discussing the rôle of economics in the context of modelling questions in information security.

Biography:

Professor David J. Pym, 6th Century Chair in Logic, and SICSA Professor of Computing Science, Head of School of Natural and Computing Sciences, University of Aberdeen. Previously Principal Scientist at HP Labs, Bristol and Professor of Logic & Computation at Bath, Professor of Logic at QMUL. PhD Edinburgh; MA, ScD Cambridge; FIMA, FBCS.

Led the ‘Security Analytics’ project at HP Labs, now deployed commercially by Hewlett-Packard in its information security business. One of the designers of the Core Gnosis tool for systems and security modelling which is used to deliver the modelling part of Security Analytics. See this recent news piece about my colleagues at HP: http://www.hpl.hp.com/news/2011/oct-dec/security_analytics.html


David is currently interested in the following areas:

• Mathematical systems modelling, using algebraic, logical, and stochastic methods, with applications in information security;
  
• Topics related to the economics of information security;
  
• Topics related to the economics of systems thinking;
  
• Topics connecting logic (substructural, modal; process algebra) and utility theory;
  
• Topics in logic related to information flow and trust domains;
  
• Topics related to information security, information stewardship, and cloud computing;
  
• Topics in logic related to the theory of search spaces.