Providing privacy for Web services by anonymous group identification

In this paper we present a SOAP extension for protecting the privacy of users of a Web service. This extension allows a user to prove to a remote SOAP server to be member of a trusted group without revealing his/her identity. Our extension has been designed as to ensure interoperability among SOAP applications written in different programming languages. We developed also some implementations of our extension using different programming languages. Moreover, we conducted an extensive experimentation of our implementation to prove its feasibility in a real-world context. In sums, our work suggests that privacy can be added to Web services with very little impact on the application developer and without compromising the performance of Web services.