After working pretty quietly for the last several years on Windows Azure Active Directory—the Microsoft identity management service for organizations—we are excited about the opportunity to start sharing more information about what our team has been up to.

As Kim Cameron, distinguished engineer on the Active Directory team, described on his blog today, we think that identity management as a service has the potential to profoundly alter the landscape of identity. In this post, I want to share how Microsoft is reimagining the Active Directory service to operate in this new world.

Identity management solutions like Active Directory, a feature of the Windows Server operating system, have been in use for a long time. Active Directory is most often used by midsize and large organizations where the substantial effort and cost necessary to build and keep an identity management system running have brought many benefits, including:

  • Single sign on (SSO) and access control across a wide range of applications and resources.
  • Sharing of information between applications—for example, information about people, groups, reporting relationships, roles, contact information, printer locations, and service addresses.
  • Information protection that enables encryption and controlled access to documents.
  • Discovery of computers, printers, files, applications, and other resources.
  • Tools to manage users, groups, and roles; reset passwords; and configure and distribute cryptographic keys, certificates, access policies, and device settings.

Organizations have built on these capabilities to create a range of solutions. One of the most important uses of Active Directory, often deployed in conjunction with identity products from other software vendors, is to provide a solid foundation to manage access to information, helping ensure that only approved users can access sensitive information. Similarly, Active Directory is often used as a basis to enable secure collaboration between people within the organization and, with Active Directory Federation Services or similar offerings, between organizations. 

But for many smaller organizations, building and maintaining an identity management system and the associated application integration has been too hard and too costly to consider. Even organizations that have successfully deployed identity management solutions are looking for ways to make identity management easier and to broaden its reach.

Here in part 1 of a two-part posting, we will look at how the use of cloud architectures and cloud economies of scale is enabling us to offer Active Directory as a turnkey service at a cost that puts this powerful collection of capabilities within reach of essentially everyone—even small organizations without an IT staff. We see this as very important. It opens the door to “democratizing” identity management so it becomes a foundational capability that every organization and every software developer can count on—no matter what platform or technology base they are building from. 

In part 2, we will look at how offering Active Directory in the cloud as turnkey services provides an opportunity to reimagine the way that directories can be used to enable the social enterprise—and how it enables developers to easily create applications that connect the directory to other software-as-a-service (SaaS) applications, cloud platforms, an organization’s customers, and social networks.

In evolving a powerful and widely deployed solution like Active Directory, we have to be very careful that we don’t create new issues while we’re addressing these new opportunities. In this overview, we provide some background on how we are reimagining Active Directory and highlight some of the key ideas driving this work.

What is Windows Azure Active Directory?

We have taken Active Directory, a widely deployed, enterprise-grade identity management solution, and made it operate in the cloud as a multitenant service with Internet scale, high availability, and integrated disaster recovery. Since we first talked about it in November 2011, Windows Azure Active Directory has shown itself to be a robust identity and access management service for both Microsoft Office 365 and Windows Azure–based applications.

In the interim, we have been working to enhance Windows Azure Active Directory by adding new, Internet-focused connectivity, mobility, and collaboration capabilities that offer value to applications running anywhere and on any platform. This includes applications running on mobile devices like iPhone, cloud platforms like Amazon Web Services, and technologies like Java.

The easiest way to think about Windows Azure Active Directory is that Microsoft is enabling an organization’s Active Directory to operate in the cloud. Just like the Active Directory feature in the Windows Server operating system that operates within your organization, the Active Directory service that is available through Windows Azure is your organization’s Active Directory. Because it is your organization’s directory, you decide who your users are, what information you keep in your directory, who can use the information and manage it, and what applications are allowed to access that information. And if you already have on-premises Active Directory, this isn’t an additional, separate copy of your directory that you have to manage independently; it is the same directory you already own that has been extended to the cloud.

Meanwhile, it is Microsoft’s responsibility to keep Active Directory running in the cloud with high scale, high availability, and integrated disaster recovery, while fully respecting your requirements for the privacy and security of your information.

Sounds straightforward, right? In practice, it really is easy to use Windows Azure Active Directory. To illustrate this, let us take a look at how a directory gets created and used when an organization signs up for Microsoft Office 365.

Windows Azure Active Directory and Office 365

Today Microsoft Office 365, Microsoft Dynamics CRM, Windows Intune software and services, and many third-party applications created by enterprises, established software vendors, and enterprise-focused startups are working with Windows Azure Active Directory. Here we focus on Office 365 and look at how Windows Azure Active Directory helps enable Office 365. 

Each time a new organization signs up for Office 365, Microsoft automatically create a new Windows Azure Active Directory that is associated with the Office 365 account. No action is required on the part of the individual signing up.

With an Active Directory in place, the owner of the Office 365 account is able to easily add users to the directory. The figure below shows how I would add a new user to my personal Office 365 account.

  

The owner of the account is also able to manage passwords for the users, determine what roles they are in and which applications they can access, and so on. An example of this type of setting is shown in the figure below.

 

Now note several interesting aspects of the experience that the owner has when signing up for Office 365:

  • Ease of use. As the previous example illustrates, it is incredibly easy to use Windows Azure Active Directory. In my case, I just signed up for Office 365—and, like magic, I got a high-scale, high-availability, disaster-tolerant Active Directory. My Active Directory was up and running in a flash, and I didn’t need to do anything to make this happen. In fact, most Office 365 customers aren’t even aware that they have an Active Directory working for them behind the scenes.
  • Single sign on across applications. Even though they may not realize Windows Azure Active Directory is there, organizations and users quickly get a lot of value from the common user experiences that the directory enables. All the applications in Office 365—Microsoft Exchange Online, SharePoint Online, Lync Online, and Office Web Apps—work with Windows Azure Active Directory, so users get single sign on. Moreover, advanced Active Directory capabilities like information protection are available using this common identity. The Windows Azure Active Directory SSO capability can be used by any application, from Microsoft or a third party running on any technology base. So if a user is signed in to one application and moves to another, the user doesn’t have to sign in again. 
  • Shared context. Once an application establishes SSO with Windows Azure Active Directory, the application can use information in the directory, including information about people, groups, security roles, and so on. This makes an application more current and relevant, and it can save users a lot of time and energy because they don’t need to re-create, sync, or otherwise manage this information for each application that they use.
  • Efficient, highly available operations. Office 365 customers don’t get a separate bill for their use of Windows Azure Active Directory; the costs of using Windows Azure and Windows Azure Active Directory are incorporated in the overall cost of the Office 365 solution. One of the key reasons that we are able to offer this rich set of identity management capabilities at reasonable cost is that we built Windows Azure Active Directory using cloud architecture and getting cloud economies of scale. We will talk more about this in a moment. 

The ease of use; great common experiences like SSO; shared context between applications, including information about the people in an organization, their relationships, and roles; and efficient, highly available operations makes Windows Azure Active Directory a great foundation for many applications and services.

Working with Existing Active Directory Deployments

As the example above shows, for new organizations, it is very easy to get started with Windows Azure Active Directory. But what if an organization is already using Active Directory for on-premises identity management? To support this, Microsoft makes it easy to “connect” Windows Azure Active Directory with an existing directory. At the technical level, organizations can enable identity federation and directory synchronization between an existing Active Directory deployment and Windows Azure Active Directory.

When an organization does this, its Active Directory is, in a sense, stretching over both an on-premises and a cloud deployment. The ability for Active Directory to operate across both on-premises and cloud deployments in a hybrid mode enables an organization to easily take advantage of new cloud-based platforms and SaaS applications, while all of its existing identity management processes and application integration can continue unaffected.

In addition, being able to operate in this hybrid mode is critical for some organizations because of business or regulatory requirements that mandate that certain critical information, such as passwords, be maintained in on-premises servers.

Running Today at Internet Scale and With High Availability

To make Active Directory available as a service, you might think all we had to do was take a copy of the Windows Server Active Directory software and run it in the cloud—that is, use Windows Azure to create a new virtual machine for each customer and then run Active Directory on this virtual machine. But that kind of approach wouldn’t give us the efficient operations or high availability that we are able to provide with Windows Azure Active Directory. 

To make the Active Directory service operate at extremely high scale and with very high availability (including the ability to do incremental servicing) and provide integrated disaster recovery, we made significant changes to the internal architecture of Active Directory and moved from a server-based system to a scale-out, cloud-based system. For example, instead of having an individual server operate as the Active Directory store and issue credentials, we split these capabilities into independent roles. We made issuing tokens a scale-out role in Windows Azure, and we partitioned the Active Directory store to operate across many servers and between data centers. 

Beyond these architectural changes, it was also clear that we needed to reimagine how Active Directory would operate in the cloud. In talking with many developers, customers, and partners, we heard that they wanted us to enhance the ability for Active Directory to “connect”—to the new Internet-based identities from Google, Facebook, and other social networks; to new SaaS applications; and to other cloud platforms.

All this work involved efforts by many people and teams across Microsoft. To get everything operating at Internet scale has been a substantial undertaking, which has taken several years. 

We have made good progress. Today we have hundreds of thousands of paying organizations using Windows Azure Active Directory as part of applications such as Office 365, Windows Intune, and many third-party applications. For example, organizations using Office 365 and the underlying Windows Azure Active Directory include Hickory Farms and Patagonia. Similarly organizations are building custom applications using Windows Azure Active Directory; for example, easyJet in Europe is using Windows Azure Active Directory Access Control and the Windows Azure Service Bus to enable flight check-in and other tasks for airport gate agents.

Coming in Part 2

In this first post, we focused on how we are reimagining Active Directory as a cloud service. We discussed how the application of cloud architecture and economics is making it possible to bring the power of organizational identity management to organizations of any size and IT sophistication, with great ease of use, low cost, and high availability. 

Hopefully this post conveyed that Active Directory as a service is here now and that it is very easy for organizations to obtain and use. Many applications are already integrating with Windows Azure Active Directory, including SaaS applications such as Office 365 and many custom applications built on Windows Azure and other platforms.

For IT professionals and users within organizations, these integrations provide many benefits, including common experiences like SSO; shared context between applications, including information about the people in an organization, their relationships, and roles; consistent management; the ability to seamlessly extend existing directory deployments and identity management processes to the cloud; and efficient, highly available operations.

In my next post, I will cover what this reimagined Active Directory can mean for developers and how moving to the cloud is enabling Microsoft and software developers to work together to reimagine the role of Active Directory. We will focus on how we are making it easier for developers to integrate with Windows Azure Active Directory and look at how Windows Azure Active Directory can be used as a platform to enable the social enterprise.

In particular, we will look at enhancements to Windows Azure Active Directory and the programming model that enable developers to more easily create applications that work with consumer-oriented identities, integrate with social networks, and incorporate information in the directory into new application experiences. And we will talk about how developers can use Windows Azure Active Directory to support new scenarios that go well beyond the “behind the firewall” role that identity management has historically played. We are excited to work with developers and help them build these next-generation experiences and capabilities for organizations and users.

 - John Shewchuk, Microsoft Technical Fellow