cyber-security-resources/SCOR/ABAC.md

Access Control: Understanding Attribute-Based Access Control (ABAC)

In the domain of cybersecurity, controlling who can access certain resources in a digital environment is paramount. This is where access control models come into play, determining how access rights are granted and what conditions must be met for these rights to be exercised. One of the most flexible and comprehensive access control models is Attribute-Based Access Control (ABAC). ABAC provides a dynamic means of enforcing access decisions based on a combination of attributes rather than static role assignments or hierarchical permissions.

What is Attribute-Based Access Control (ABAC)?

Attribute-Based Access Control (ABAC) is an access control model that evaluates attributes (or characteristics) of the user, the resource to be accessed, and the context of the access request to make authorization decisions. Unlike traditional models that rely on predefined roles or groups (like Role-Based Access Control - RBAC), ABAC uses policies that can evaluate multiple attributes, providing a more granular and flexible approach to access control.

Key Components of ABAC:

• Subject Attributes: Characteristics of the entity trying to access a resource. This can include user attributes like role, department, or clearance level.
• Object Attributes: Characteristics of the resource or object being accessed. This can include classifications, ownership, or sensitivity levels.
• Environment Attributes: Contextual details about the access request. This can include time of day, location, or the device being used.
• Policies: Rules that define the access conditions based on the attributes mentioned above. Policies are used to evaluate whether access should be granted or denied.

How Does ABAC Work?

In ABAC, access decisions are made by evaluating policies against the attributes of the subjects, objects, and the context of the access request. When a user (subject) attempts to access a resource (object), the ABAC system assesses the relevant attributes and applies the policies to determine if the access should be permitted or denied. This process allows for highly dynamic and context-sensitive access control decisions.

For example, a policy might allow access to a financial report only if the user is in the finance department (subject attribute), the report is classified as internal use (object attribute), and the request is made during working hours (environment attribute).

Advantages of ABAC

• Granularity: Allows for highly granular access control decisions based on multiple attributes, leading to more precise control over who can access what, when, and under what conditions.
• Flexibility: Can easily adapt to complex and changing requirements without the need to reconfigure roles or permissions fundamentally.
• Scalability: Suitable for large, distributed environments where attributes and policies can be managed centrally.
• Context-Awareness: Takes into account the context of access requests, allowing for more dynamic and situation-aware policies.