1. Cloud Identity:

• Overview: Users are created, managed, and authenticated directly within a cloud service, such as Office 365. The cloud service itself acts as the identity provider, handling all aspects of identity management and authentication.
• Use Cases: This approach is ideal for organizations that are fully cloud-based or those that do not require on-premises infrastructure for identity management.
• Key Features:
  • User Creation and Management: All user accounts are created, managed, and maintained directly in the cloud service.
  • Authentication: The cloud service provides the authentication mechanisms, ensuring users can access the cloud resources with their cloud-managed credentials.

2. Directory Synchronization:

• Overview: Users are created and managed in an on-premises identity provider (such as Active Directory) and synchronized to the cloud service. This hybrid approach allows organizations to maintain control over user identities on-premises while leveraging cloud services.
• Use Cases: Suitable for organizations that have existing on-premises identity infrastructure and wish to extend their identity management to the cloud without fully migrating user management.
• Key Features:
  • Synchronization: Tools like Azure AD Connect are used to synchronize on-premises directories with the cloud service. Changes made on-premises are automatically reflected in the cloud.
  • Hybrid Management: Allows for centralized management of user identities while enabling cloud services for users.

3. Federated Identity:

• Overview: The on-premises identity provider handles the authentication process, and the cloud service relies on this provider for user authentication. This setup is commonly used to implement Single Sign-On (SSO).
• Use Cases: Ideal for organizations that want to retain control over authentication and leverage existing on-premises identity infrastructure while enabling cloud access.
• Key Features:
  • Single Sign-On (SSO): Users can access cloud services using their on-premises credentials without needing to reauthenticate, providing a seamless experience.
  • Federation Services: Typically implemented using technologies like Microsoft Active Directory Federation Services (AD FS) or third-party identity providers.
  • Standards-Based: Often leverages standards such as SAML 2.0 for secure authentication and identity federation.

Examples:

• Microsoft AD using AD FS: Integrates on-premises Active Directory with cloud services like Office 365, allowing users to authenticate using their AD credentials.
• Third-Party Identity Providers: Organizations may use third-party identity providers (e.g., Okta, Ping Identity) to manage federated authentication.
• Shibboleth: An open-source software that implements SAML 2.0 to enable federated identity, commonly used in educational and research institutions.

Summary:

• Cloud Identity is fully cloud-based, where all identity management occurs within the cloud service.
• Directory Synchronization allows for a hybrid approach, syncing on-premises identities with the cloud.
• Federated Identity enables SSO and retains authentication control within the organization, typically leveraging existing on-premises identity providers.

These methods provide flexibility for organizations to manage user accounts in the cloud based on their specific needs and existing infrastructure.