What Can Context Do for Trust in Manets?

The global performance of a mobile ad hoc networks (manet) greatly depends on, both, the cooperation of participating nodes and the environment in which the nodes evolve. The willingness of a node to cooperate can be illustrated by the trust assessed to the node. Yet, existing trust models, designed for reliable wired networks, do not take into consideration possible communication failures between client and server. We believe, that in the case of ad hoc networks such factors should be considered when computing trust. In this article, we show how an interaction can be decomoposed in three separate phases : two communication phases for transporting the request to the server and the response back to the client, and one execution phase which represents the actual execution of the service by the server. We propose to define the communication environment using contextual attributes and to consider this context when assessing trust to a server. We discuss the possible uses of context in the field of trust computation in manets and define contextual attributes that seem important to consider when modelling and computing trust.