Web service secuirty

WS-Security Policy specification defines a standard way to define how to secure messages exchanged between Web services and clients.  WS-Security policy language can be used to publish security requirements and constrains of a Web service using the WSDL specification. That is, using WS – security policy language, we can drive a Web service security engine to secure out going messages in a certain way and instruct the verification of incoming messages in a standard, defined way. In this article by Nandana Mihindukulasooriya, he looks at main components of the WS–Security Policy Language and how these components can be combined to build a security policy that fulfills security requirements of a Web service.