Tracing cooperating Web Services

Web Services is a strong candidate to carry out the Service Oriented Architecture, SOA, that has been established for the coming FMLS, the Command and Control System for the Swedish Defence. Many tasks will be solved by Web Services in cooperation. An important security requirement is the possibility to trace the identities of the Web Services that solved the task. We introduce a model for tracing cooperating Web Services. The model is new, in the sense that it models a type of cooperation, by asynchronous one way messaging, which as yet has not been implemented very often. The model means that the messages sent between the Web Services contain data including the identities of the cooperating Web Services. The data constitute a hierarchic tree, and they are signed in a way that prevents the participators to masquerade in the name of someone else or to hide their participation.