Modelling and evaluating trust relationships in mobile agents based systems

This paper considers a trust framework for mobile agent based systems. It introduces the concept of trust reflection and presents a novel method using views of the truster to derive the trust symmetry. This new approach addresses the trust initialization issues and allows for different levels of initial trust to be established based on trustor's initial assessment and then enables different trust dynamics to evolve in the course of future interactions in situations where full trust appraisal is not possible at the beginning of interactions. This is an important aspect for security in distributed systems, especially in mobile agent based systems due to the fact that the agent owner principals may not have all the information to appraise full trust in other entities(e.g. foreign hosts to be visited by the mobile agent) when composing an itinerary prior to the deployment of mobile agent. Our framework proposes a new formalism to capture and reason about trust reflection and presents an algorithm for updating trust during system operation. This is then applied to a simulated mobile agent system and an analysis of the results is presented.