You work for a government research facility. Your organization often shares data with other government research organizations.

You would like to create a single sign-on experience across the organizations, where users at each organization can sign in with the user ID/authentication issued by that organization, then access research data in all the other organizations. Instead of replicating the data stores of each organization at every other organization (which is one way of accomplishing this goal), you instead want every user to have access to each organization’s specific storage resources.

If you don’t use cross-certification, what other model can you implement for this purpose?