Full Definition
What is an Identity Provider?
An Identity Provider (IdP) is a service that stores and manages digital identities. It authenticates users and provides authentication tokens to service providers, enabling Single Sign-On (SSO) and centralized identity management.
Core Functions
Identity Management
- User provisioning
- Profile management
- Group management
- Lifecycle management
Authentication
- Credential verification
- Multi-factor authentication
- Password management
- Passwordless options
Token Issuance
- SAML assertions
- OAuth tokens
- OIDC ID tokens
- JWT creation
IdP vs. Service Provider
| Identity Provider | Service Provider |
|---|---|
| Authenticates users | Relies on IdP |
| Issues tokens | Validates tokens |
| Manages identities | Consumes identity |
| Examples: Okta, Azure AD | Examples: Salesforce, Slack |
Common IdP Solutions
Enterprise
- Microsoft Entra ID (Azure AD)
- Okta
- Ping Identity
- OneLogin
Consumer/Developer
- Auth0
- Google Identity
- AWS Cognito
- Firebase Auth
Open Source
- Keycloak
- Gluu
- FreeIPA
Protocols Supported
- SAML 2.0
- OAuth 2.0
- OpenID Connect (OIDC)
- LDAP
- SCIM (provisioning)
Selection Criteria
- Protocol support
- MFA capabilities
- Directory integration
- Scalability
- Compliance features
- Cost model