Identity Provider

An identity provider (IdP) is a service that authenticates a user and supplies identity information to an application the user wants to access. An organization can connect its IdP to multiple applications so it can manage sign-in centrally. Examples of IdPs include Okta, Microsoft Entra ID, and Google Workspace.

How an identity provider works

In a SAML sign-in flow, the IdP authenticates the user and sends an assertion to the service provider (SP). The SP validates that assertion before granting access. Sign-in can begin at either the application or the IdP.

In OpenID Connect (OIDC), the corresponding role is the OpenID Provider. An OpenID Provider is an OAuth 2.0 authorization server that authenticates the user and provides identity claims to the application, called a relying party, through an ID token.