Federated identity management (FIM) is a type of identity management across multiple entities, such as universities and service providers. These entities form a so-called federation in which they trust each other to a certain extent. The user information of a user remains with his or her home organization. This is used to identify and authenticate with the home organization, in the picture a university. This forwards certain information to the service provider. The user can then use a service without having to create his own account there. Of course, the participants must have a language, i.e. a common protocol or suitable translator. In the higher education sector, eduGAIN is an international inter-federation, i.e. a federation through national federations such as the German DFN-AAI. In the public sector, eIDAS is an example of eIDs. The examples mentioned use SAML as a protocol. A similar principle is used by Google and Facebook, for example. Common protocols for such web services are OAuth and OpenID Connect.