X.509 Authentication and Authorization in Fermi Cloud

We present a summary of how X.509 authentication and authorization are used with Open Nebula in Fermi Cloud. We also describe a history of why the X.509 authentication was needed in Fermi Cloud, and review X.509 authorization options, both internal and external to Open Nebula. We show how these options can be and have been used to successfully run scientific workflows on federated clouds, which include Open Nebula on Fermi Cloud and Amazon Web Services as well as other community clouds. We also outline federation options being used by other commercial and open-source clouds and cloud research projects.