When you are using a cloud service, whether it be Office 365, Facebook, LinkedIn or Gmail you are using a user account, and these are also referred to as ‘identities’. Typically there are three types of identities in a cloud service: Cloud Identities, Synced Identities and Federated Identities.
- Cloud Identity – a Cloud Identity is a user account that’s created and managed in the cloud service. In case of Office 365 this account is created and managed in the Microsoft Online Portal. Important to note is that when you access an Office 365 service, authentication takes place against the Windows Azure Active Directory Domain Controllers.
In the Microsoft Online Portal these accounts are easily identifiable as Cloud Identities as can be seen in the following figure:
- Synced Identity – a Synced Identity is created and managed in your local Active Directory and synchronized with the Cloud service. In Office 365 you can opt to synchronize the passwords as well, although not the actual password is synchronized but a hash of the password. Like Cloud Identities authentication takes place against the Windows Azure Active Directory Domain Controllers. These accounts are identified in the Microsoft Online Portal as ‘Synced with Active Directory’ as shown in the following figure:
Although the username and password are identical in Office 365 and in the local Active Directory, this is not a Single Sign-On solution, but I always refer to this as a ‘Same Set of Credentials’ solution.
- Federated Identity – a Federated Identity is a user account that’s created and managed in your local Active Directory and that’s synchronized with Office 365. When the account is synchronized an account in Office 365 (Windows Azure Active Directory) is created. When a service in Office 365 is accessed, the user is not authenticated against the Windows Azure Active Directory Domain Controllers, but the authentication request is redirected to your local Active Directory and Domain Controllers. To achieve this an Active Directory Federation Service (ADFS) needs to be in place. Since there’s only one set of credentials (all authentication takes place against your local Domain Controllers!) this is referred to as ‘Single Sign-On’.