Introduction
Authentication proves who you are; authorisation determines what you can do. Confusing the two can lead to both security gaps and user frustration. This article explains the main approaches to authorisation—Role‑Based Access Control (RBAC), Attribute‑Based Access Control (ABAC) and dynamic policies—and how to combine them for effective access management.
Role‑Based Access Control (RBAC)
RBAC grants permissions based on membership in a group or role. For example, all users in the “Finance” role can access the expense system. RBAC is intuitive, aligns with organisational structures and is straightforward to implement. Identity stores such as Active Directory map well to RBAC, allowing for automation via group membership. However, roles can proliferate rapidly, and they don’t account for contextual factors like time, location or device.
Attribute‑Based Access Control (ABAC)
ABAC extends RBAC by considering additional user attributes—such as location, device type, employment status or regulatory requirements—when deciding access. For instance, a policy might state, “Allow access if the user is a full‑time employee and is logging in from a corporate‑managed device.” ABAC offers granular control but can be harder to design and maintain because it depends on accurate and up‑to‑date attribute data.
Dynamic Access Policies
Dynamic policies evaluate contextual information at the moment of access. Factors include time of day, geolocation, IP address, device security posture and even user behaviour. These policies enable adaptive access—granting or denying access based on real‑time risk. They complement both RBAC and ABAC: static roles and attributes establish baseline rights, while dynamic context fine‑tunes them.
For example, an administrator might be allowed to access a production server only after hours and only from an on‑site network. If a login attempt occurs at 10 a.m. from a remote IP address, the policy blocks access or requires additional verification.
Access Management and Privileged Access Management
Access Management platforms use RBAC, ABAC and dynamic policies to authenticate users and authorise access to applications. Privileged Access Management (PAM) applies these principles to high‑risk activities—such as server administration or database management. PAM tools often add capabilities like session monitoring, just‑in‑time access and detailed audit trails.
Building Your Authorisation Strategy
A robust strategy blends roles, attributes and context:
• Start with RBAC: Define broad roles that map to organisational functions. • Layer on ABAC: Refine access using user and resource attributes—such as location, department or sensitivity level. • Implement dynamic controls: Use risk‑based policies to adapt decisions in real time. • Review regularly: User attributes and business needs change. Periodic access reviews help keep permissions aligned with reality.
Conclusion
Authorisation isn’t a one‑size‑fits‑all exercise. Combining RBAC, ABAC and dynamic policies helps ensure that users get the access they need—no more and no less—based on who they are, what they do and the context of their request. A thoughtful authorisation strategy reduces risk while maintaining a smooth user experience.
