Identity Provider (IdP)

A system that authenticates users and issues assertions or tokens vouching for their identity to other applications. In federated single sign-on, the identity provider (for example Okta, Microsoft Entra ID, or Ping) authenticates the user once and the relying service provider trusts its assertion, using SAML or OpenID Connect. Decentralized identity removes the runtime dependency on a central IdP by letting the holder present signed credentials directly.