Introduction
Federated Identity is a method whereby a user can access multiple systems or organizations with a single digital identity without needing to log in again. This is made possible by an Identity Provider (IdP), which handles authentication and maintains trust relationships with various applications or organizations.
This approach is widely used in cloud environments, corporate networks, and collaborations between organizations.
How Does Federated Identity Work?
Federated Identity utilizes an Identity Provider (IdP) that acts as a central entity for authentication. When a user logs into a service, they are redirected to the IdP for verification. After successful authentication, the IdP sends a token back to the service, granting access without requiring the user to log in again.
Steps:
- The user attempts to access an application (Service Provider).
- The application redirects the user to the Identity Provider (IdP).
- The user logs in to the IdP and is verified.
- The IdP sends an authentication token back to the application.
- The user gains access without logging in again.
Advantages of Federated Identity
- One identity for multiple applications → Reduces the need for multiple accounts and passwords.
- Better user experience → Users need to log in less frequently.
- Stronger security → Access management is centralized and can be combined with Multi-Factor Authentication (MFA).
- Simpler management for IT → Fewer password resets and better control over access.
- Better for collaboration between organizations → Convenient for companies working with partners or external vendors.
Disadvantages and Risks
- Single Point of Failure (SPoF) → If the IdP is unavailable, users cannot log in.
- Trust between parties → Service Providers must trust that the IdP is secure and reliable.
- Complexity → Setting up federated authentication requires technical expertise.
Identity Providers (IdP)
Some well-known Identity Providers include:
- Microsoft Entra ID (Azure AD)
- Okta
- Google Workspace Identity
- Ping Identity
- Keycloak (open-source)
- Auth0
- Shibboleth (academic sector)
Federated Identity Standards and Protocols
Federated Identity employs various protocols for secure authentication and authorization:
1. Security Assertion Markup Language (SAML)
- XML-based protocol for authentication and authorization.
- Widely used in corporate environments for Single Sign-On (SSO).
- Commonly applied in SaaS applications and enterprise solutions.
2. OpenID Connect (OIDC)
- Identity layer on top of OAuth 2.0.
- Suitable for modern web and mobile applications.
- Frequently used by cloud providers and SaaS platforms.
3. OAuth 2.0
- Authorization protocol that enables federated access without users sharing their password.
- Commonly used for API access and third-party logins (e.g., “Log in with Google”).
4. WS-Federation
- Microsoft protocol for federated authentication.
- Often used with Active Directory Federation Services (AD FS).
5. Kerberos
- Network protocol for Single Sign-On within corporate networks.
- Used in Windows Active Directory to secure internal resources.
Use Cases
Federated Identity is used in various scenarios, including:
- Enterprise SSO: Employees use one login for multiple corporate applications.
- Cloud & SaaS access: Companies integrate Microsoft Entra ID, Okta, or Google Workspace with external SaaS apps.
- Academic federations: Universities use Shibboleth for access to research networks.
- Business-to-Business (B2B) collaboration: Partners share a federated login without needing to manage accounts.
Conclusion
Federated Identity offers an efficient and secure way to provide users access to multiple systems without managing multiple accounts. By utilizing protocols such as SAML, OpenID Connect, and OAuth 2.0, organizations can implement secure and scalable authentication.