Implementation of tracing in a circuit of web services

Web Services is a strong candidate to carry out the Service Oriented Architecture, SOA, which has been established for the future Command and Control System for the Swedish Armed Forces. A successful progress of the Web Services concept demands flexible ways for Web Services to cooperate and to jointly fulfil a task that is requested by a client. In some applications, the execution of the task is not completely specified beforehand, but could rather be referred to as "best effort". One example is information searches. To achieve trust in the outcome of the task, it is essential that the identities of the cooperating Web Services can be tracked in a secure way. This report describes an approach to securely track identities of Web Services, subsequently invoked by chains of one-way messages. The model is based on a message structure, which the requesting client can use to iteratively build a hierarchic tree. The model facilitates flexibility and robustness. The main parts of the model have been implemented, to verify its usefulness. The conclusion is that the model is readily implemented, but that pre fabricated Web Services platforms are not the best choice for implementation.