Mutual trust in open environment for cascaded web services

Given an open cascading Web services environment, this paper deals with the following problems: 1) how to compute trust index of a service provider or a service requestor, which is dynamic and is continuously updated to reflect service providers'/requestors' recent behaviors. 2) how to propagate trust ratings for a service provider/requestor 3) how to determine if a service requestor/provider violates the usage policies specified by the service provider/requestor.