A Belief-based Trust Model for Dynamic Service Selection

Provision of services across institutional boundaries has become an active research area. Many such services encode access to computational and data resources (comprising single machines to computational clusters). Such services can also be informational, and integrate different resources within an institution. Consequently, we envision a service rich environment in the future, where service consumers can intelligently decide between which services to select. If interaction between service providers/users is automated, it is necessary for these service clients to be able to automatically chose between a set of equivalent (or similar) services. In such a scenario trust serves as a benchmark to differentiate between service providers. One might therefore prioritize potential cooperative partners based on the established trust. Although many approaches exist in literature about trust between online communities, the exact nature of trust for multi-institutional service sharing remains undefined. Therefore, the concept of trust suffers from an imperfect understanding, a plethora of definitions, and informal use in the literature. We present a formalism for describing trust within multi-institutional service sharing, and provide an implementation of this; enabling the agent to make trust-based decision. We evaluate our formalism through simulation.