Towards evidence-based trust brokering

In a global computing environment, trust management is important for entities to collaborate. Traditional access control methods cannot meet the needs of autonomous decision making with partial information. The SECURE project introduced a collaboration model using the combination of trust and risk models. This allows an entity to formulate trust according to its own observations and also by accepting recommendations from other entities. Evidence, which originates from other entities, must be gathered in a secure way to ensure that integrity is maintained. This paper introduces a trust broker model which describes how one entity can locate and retrieve evidence on another entity's historic behavior. This evidence-based trust brokering approach provides a basic model for secure evidence gathering and is appropriate for the global computing environment.