PBAC

PBAC stands for Policy-Based Access Control. It is an access control paradigm that governs application and data resources by evaluating requests against a set of policies. Unlike models that rely primarily on the user’s identity or static roles, PBAC uses attributes of the subject, the resource, the action, and the environment to determine authorization. Policies specify conditions under which access is permitted, often including context such as time, location, or device state.

Core components typically include the policy administration point (PAP) for authoring and managing policies, the policy decision point (PDP) that evaluates requests against those policies, the policy enforcement point (PEP) that enforces the decision at the resource, and the policy information point (PIP) that gathers attribute data from sources such as identity directories or external services. Policy languages commonly used with PBAC include XACML and ALFA, among others.

PBAC is closely related to ABAC and is sometimes used interchangeably; in practice PBAC emphasizes policy-driven decisions using attributes, which enables fine-grained, context-aware access control. It can express RBAC concepts by treating roles as attributes but is not limited to role-based schemes.

Typical use cases include cloud and microservices access control, data protection and compliance, healthcare and finance, and any environment requiring dynamic authorization with auditable decisions. Challenges include policy complexity and conflicts, latency or performance overhead, and ensuring reliable attribute data and governance over policy lifecycles.