Performance of Web Services Security

Web services enable application integration and data sharing in a platform neutral, language independent environment for both business and science. This increases the degree of exposure of critical resources which poses new challenges to securing data and service. The existing technologies such as VPN, firewall, NAT and SSL are examples of either intra-corporate domain or point-to-point solution, whereas compositional services and complex service invocation chain very often stand across multiple trust domains. In order to cope with the challenges, WS-Security and associated emerging standards define SOAP-level mechanisms to move security related information along with the message content. Designed to achieve end-to-end security, the new standards have also been utilized by the NaradaBrokering [19] messaging infrastructure, a features rich and values added interoperable interface to Web services. These security centered standards, however, have brought about significant overheads to the use of service. Concerns about the operational performance of Web services security are legitimate because the new suite of XML specifications significantly enlarge SOAP size especially its header size. The lately added XML security elements not only make use of more network bandwidth as SOAP transports, they also demand additional CPU cycles at both the assembly-sender side and at the processing-receiver side. Their utilization into the messaging substrate is at debate. Therefore it's desirable to be able to examine the performance issue of Web services security, and it would be considered constructive to examine it based on the specific implementation, based on the actual data gathered from these implementations.