Shibboleth is a single sign-on log-in system for computer networks and the Internet. It allows people to sign in using just one identity to various systems run by federations of different organizations or institutions. The federations are often universities or public service organizations. The Shibboleth Internet2 middleware initiative created an architecture and open-source implementation for identity management and federated identity-based authentication and authorization (or access control) infrastructure based on Security Assertion Markup Language (SAML). Federated identity allows the sharing of information about users from one security domain to the other organizations in a federation. This allows for cross-domain single sign-on and removes the need for content providers to maintain user names and passwords. Identity providers (IdPs) supply user information, while service providers (SPs) consume this information and give access to secure content. History The Shibboleth project grew out of Internet2. Today, the project is managed by the Shibboleth Consortium. Two of the most popular software components managed by the Shibboleth Consortium are the Shibboleth Identity Provider and the Shibboleth Service Provider, both of which are implementations of SAML. The project was named after an identifying passphrase used in the Bible (Judges ) because Ephraimites were not able to pronounce "sh". The Shibboleth project was started in 2000 to facilitate the sharing of resources between organizations with incompatible authentication and authorization infrastructures. Architectural work was performed for over a year prior to any software development. After development and testing, Shibboleth IdP 1.0 was released in July 2003. This was followed by the release of Shibboleth IdP 1.3 in August 2005. Version 2.0 of the Shibboleth software was a major upgrade released in March 2008. It included both IdP and SP components, but, more importantly, Shibboleth 2.0 supported SAML 2.0. The Shibboleth and SAML protocols were developed during the same timeframe. From the beginning, Shibboleth was based on SAML, but, where SAML was found lacking, Shibboleth improvised, and the Shibboleth developers implemented features that compensated for missing features in SAML 1.1. Some of these features were later incorporated into SAML 2.0, and, in that sense, Shibboleth contributed to the evolution of the SAML protocol. Perhaps the most important contributed feature was the legacy Shibboleth AuthnRequest protocol. Since the SAML 1.1 protocol was inherently an IdP-first protocol, Shibboleth invented a simple HTTP-based authentication request protocol that turned SAML 1.1 into an SP-first protocol. This protocol was first implemented in Shibboleth IdP 1.0 and