Using a cell phone, a principal is able to access a ring-tone vendor's site. Due to implementation of single sign-on, the ring-tone vendor recognizes the principal from the cell-phone provider's authentication. This allows the principal to purchase ring tones by interacting with the user's bank for payment. The following figure illustrates the process of requesting a service and being authenticated for access. It assumes the following:
MyWireless is a cellular service provider and an identity provider in a federation framework that contains access to the discovery service in a web services framework.
MyRingtones is a service provider in a federation framework that also acts as a web service consumer (WSC) in a web services framework. It sells ringtones for use with cellular phones.
MyBank is a web service provider (WSP) in a web services framework. Linking MyBank to My Ringtones offers the opportunity for seamless purchases.
The same web service can act as a different entity in different scenarios.
The user attempts to access MyRingtones and, after being prompted for credentials stored in MyBank, receives authorization through MyWireless. Single sign-on is accomplished in the back end. The entire process is based on implementations of the Liberty ID-FF, Liberty ID-WSF, and Liberty ID-SIS specifications.