Identity federation is not a new technology or area of interest, but it has taken on renewed importance in the cloud as the cloud becomes a place for organizations to work together on common projects. Organizations can share identities in many ways in the cloud. This can run the gamut of anything from encrypted tunnels into cloud based applications using VPNs or SSH to establishing new identities for users of specific cloud applications. For our students it is important that they have a basis to understand the importance of identity and the set of ideas around this issue.