Security for Web Services

Abstract

This article discusses the main security requirements for Web services and it describes how such security requirements are addressed by standards for Web services security recently developed or under development by various standardizations bodies. Standards are reviewed according to a conceptual framework that groups them by the main functionalities they provide. Covered standards include most of the standards encompassed by the original Web Service Security roadmap proposed by Microsoft and IBM in 2002 (Microsoft and IBM 2002). They range from the ones geared toward message and conversation security and reliability to those developed for providing interoperable Single Sign On and Identity Management functions in federated organizations. The latter include Security Assertion Markup Language (SAML), WS-Policy, XACML, that is related to access control and has been recently extended with a profile for Web services access control; XKMS and WS-Trust; WS-Federation, Liberty Alliance and Shibboleth, that address the important problem of identity management in federated organizations. The article also discusses the issues related to the use of the standards and open research issues in the area of access control for Web services and innovative digital identity management techniques are outlined.