In this use case, Company A is acquired by Company B. The intranets for both companies have been merged, but much of the network infrastructure remains as though they were still two separate entities. Company A maintains an Active Directory domain, and Company B maintains an OpenSSO Enterprise single sign-on infrastructure in its own domain.
In order for Company A employees to access some internal applications available to Company B employees, a trust relationship is created between the Company A domain and the Company B domain. The trust relationship is created using the Web Services Federation protocol. Company A employees, signed on to their Microsoft Windows computers, can now navigate to the Company B paycheck application by using a Web Services Federation secure token.