Shibboleth is an Internet2 Middleware Initiative project that has created an architecture and open-source implementation for federated identity-based authentication and authorization infrastructure. Federated identity allows for information about users in one security domain to be provided to other organizations in a secure fashion. This allows for cross-domain single sign-on and removes the need for content providers to maintain usernames and passwords.Shibboleth supports multiple federated identity protocols; SAML 1.0, 1.1, 2.0, Microsoft ADFS, and soon Microsoft Cardspace. It is composed of two main components: Identity providers (IdPs) which supply user information, and service providers (SPs) which consume this information. A third, optional, component know as the discovery service assists users in getting from a service provider to their IdP.