Semiring-based Frameworks for Trust Propagation in Small-World Networks and Coalition Formation Criteria

Multitrust provides a flexible approach to encoding trust metrics whereby definitions for trust propagation and aggregation are specified in terms of a semiring. Determining the degree of trust between principals across a trust network (TN) is, in turn, programmed as a (semiring-based) soft-constraint satisfaction problem. In this paper, we consider the use of semiring-based metrics in reasoning about trust between coalition-forming principals. The configurable nature of multitrust makes it well-suited to modeling trust within coalitions: whether adding more principals to a coalition increases trust or decreases trust is captured by the definition of trust aggregation within the semiring.