RBAC vs. ABAC: What’s the Difference?

Developers looking to create and manage access control for their applications often have to weigh elements like security, user experience, and ease of implementation against each other. 

To that effect, this blog will cover two widely used authorization methods that govern access control through roles or attributes.

RBAC (Role-Based Access Control) simplifies access by assigning predefined roles to users. In contrast, ABAC (Attribute-Based Access Control) takes a more intricate approach, determining access based on various user traits, object features, action types, and beyond. 

While both methods function similarly for end users, the underlying mechanisms that power them feature key differences that developers and adopters need to consider. Making an educated decision requires knowing how each access control system works, their pros and cons, and how they compare in capacity, applicability, and management requirements. 

In this article, we’ll dive into the nuanced realm of ABAC vs. RBAC, breaking down everything you need to know to make the right choice for your next project. You can also view the video below for a developer-focused introduction to authorization concepts.

What is RBAC?

Role-based access control is an approach to authorization that relies on pre-defined access permissions for the role (or roles) a user is given. Once roles and their respective privileges are established and assigned to every user, secure access control is essentially automatic.

How does this work in practice? Users are assigned one or more roles associated with their position, seniority, or other organizational function. When users attempt to access sensitive information or perform an action (i.e., editing, moving, deleting), the system will check if the action is permitted for their role(s).

There is a spectrum of flexibility available in RBAC. 

• In traditional RBAC, users may accumulate roles over time, gradually adding to their access permissions. 

• In constrained RBAC, there are limits on the number of roles users carry simultaneously. 

• In hierarchical RBAC, roles relate specifically to organizational stature, with greater access for executives and less for other staff.

Advantages and potential drawbacks of using RBAC

The most significant benefit of RBAC is simplicity. Rather than checking against complex rules and relationships, an RBAC system makes a more straightforward assessment. For IT teams, account troubleshooting is relatively simple as well, as all access questions are routed through simple variables and questions, like “Does the user have the correct role?” and “Should they?”

Another major advantage relates to the ecosystem in which a given app or program resides. If an organization relies heavily on Microsoft software, for example, it may opt for RBAC by way of Microsoft’s Azure RBAC, which functions seamlessly across all related or connected software.

However, there are potential issues with RBAC. Roles are generally rigid and offer little room for customization to individual employees’ needs. So, in practice, users may be assigned many roles over time, and the resulting bloat (also called role explosion) can make revoking or managing access difficult.

What is ABAC?

Attribute-based access control governs authorization through rules concerning more than just users’ roles. The system makes decisions through attributes, which are broadly “if then” statements relating to:

• Users and actions: These are attributes related to the user, which may include the role alongside more granular factors (i.e., location, IP address, length of access session), as well as the actions they’re attempting (i.e., type, frequency, etc.), assessed in real-time.

• Assets acted upon: The specific assets users are attempting to access also carry a set of attributes which can be configured in endless combinations. For example, the file type, location, history, and specific content can all be focal points.

• Environmental context: The context surrounding the action, such as fit and necessity for daily operations, the broader threat environment, and comparison against a defined security baseline (i.e., business-as-usual), may also determine whether the action is authorized.

In practice, these factors amount to a system with greater potential for customization, but it also means greater resource costs for implementation and maintenance. On the user side, the login process can be just as seamless—if not more—than in comparable RBAC systems.

Advantages and potential drawbacks of using ABAC

ABAC systems offer unparalleled customization in terms of authorization. Any rule between a user, an asset, and the environment can be enough to allow access or trigger a restriction. That means organizations can tailor automation to increasingly complicated privacy needs (such as evolving regulatory requirements) when expanding within or across industries or locations.

As with RBAC, fitting with existing infrastructure can be a significant benefit. Organizations that run on Amazon Web Services (AWS) may need or want to use ABAC for AWS for compatibility alone.

There are also potential downsides to the complexity that comes with ABAC. First and foremost, it requires greater attention to detail both during initial implementation and throughout the ongoing management process. In addition, adjustments to rules and relationships over time become increasingly complex and challenging as the number and diversity of assets scale up.

RBAC vs. ABAC: Which one is right for you?

Generally speaking, RBAC is a simpler and streamlined system that works best for smaller teams with fewer variables. ABAC is more complex. It shines in more mature environments that require greater attention to detail for auth and potentially greater resource costs.

Here’s how the two approaches stack up in terms of how they work for IT teams and users:

The deciding factors between these two approaches to access control often come down to organizational structure and the need to sell to enterprise customers. 

RBAC might make the most sense if your organization features clearly defined roles and responsibilities concerning staff access. If you have complex access rules, then ABAC may be better. 

Along the same lines, if you have a B2B product that sells to other enterprises, your access control should align with the access control expectations and requirements your customers have for products they use. 

Can you use both RBAC and ABAC?

Yes! Many software projects can accommodate both RBAC and ABAC. Depending on the user base, it might be advantageous to configure access for certain accounts on a simpler RBAC model and others on ABAC. 

For example, in a hybrid hierarchical system, you could apply RBAC for lower-ranking employees, third-party contractors, or clients who do not come into contact with much (if any) sensitive data. Simultaneously, you could apply a more delicate ABAC system to executive, IT, and other accounts that access these protected resources often.

Supporting both approaches will make your software appealing to a broader market.

Fine-grained authorization with Descope

Implementing in-house access control can be daunting. Descope’s no-code Customer Identity and Access Management (CIAM) platform is tailored for B2B app builders, so you can seamlessly integrate RBAC, ReBAC, and ABAC into your applications without the hassle.

Descope also eliminates endless developer implementation cycles with additional features like Single Sign-On (SSO), SCIM provisioning, tenant management, and Multi-Factor Authentication (MFA).

Elevate your app-building experience with Descope by signing up for a Free Forever account. Have questions about fine-grained authorization or our platform? Book time with our auth experts to learn more.