Identitätsprovider

Identitätsprovider, often abbreviated as IdP, are entities that create, maintain, and manage identity information for principals and, at the time of a request, issue authentication and authorization information to relying parties. In simpler terms, an IdP is a system that authenticates a user's identity and then provides that verified identity information to other services, allowing the user to log in without needing separate credentials for each service. This process is a core component of federated identity management.

The primary function of an IdP is to verify who a user is. This is typically done through established authentication methods such as username and password, multi-factor authentication (MFA), or biometric scans. Once authenticated, the IdP issues a security token, often in the form of a SAML assertion or a JWT (JSON Web Token), containing information about the user's identity and potentially their granted permissions. This token is then sent to a relying party (also known as a Service Provider or SP), which trusts the IdP to have correctly verified the user.

Examples of Identitätsprovider include large social media platforms like Google or Facebook, which allow users to log in to third-party websites and applications using their existing accounts. In enterprise environments, dedicated identity management solutions like Okta, Azure Active Directory, or Keycloak serve as IdPs, enabling single sign-on (SSO) across various internal and external applications. This streamlines user access and enhances security by centralizing authentication management.