Secure service composition in sensor Web

Geospatial Web services have become popular. Geospatial processing has been moving into the Web environment. A geospatial workflow, combining a series of geospatial Web services, is common in achieving a complex of computation from simple individual Web services. Web service security is important for guarding sensitive data and assuring correct delivery of data. Many Web services need to be secured in terms of access control and message/data integrity. Workflow security is not a simple problem to be completely handled at individual Web service but has its complexity. This study examines the approaches to enforce security measures on a workflow and to extend workflow scripting language with capabilities in handling security tokens. In this study, workflows are defined in business process execution language (BPEL). A BPEL execution engine was augmented with the extensions to access headers of simple object access protocol (SOAP) messages. The study experimented several strategies to enable the successful passing of security tokens through the engine which is often required. The extensions worked successfully in supporting the passing of security tokens to individual services through the BPEL engine. In future, the solution needs further testing and improvements, examining on multiple security tokens, extending beyond limitations of SOAP binding, and forming standards.