Abstract: A method and a system are presented in which federated domains interact within a federated environment. Domains within a federation can initiate federated single-sign-on operations for a user at other federated domains. A point-of-contact server within a domain relies upon a trust proxy within the domain to manage trust relationships between the domain and the federation. Trust proxies interpret assertions from other federated domains as necessary. Trust proxies may have a trust relationship with one or more trust brokers, and a trust proxy may rely upon a trust broker for assistance in interpreting assertions. When a user is provisioned at a particular federated domain, the federated domain can provision the user to other federated domains within the federated environment. A provision operation may include creating or deleting an account for a user, pushing updated user account information including attributes, and requesting updates on account information including attributes.