Role-Based Access Control (RBAC) and Relationship-Based Access Control (ReBAC)

1| Use Case | RBAC | ReBAC |
2| --- | --- | --- |
3| Assigning permissions | Permissions are assigned to roles, and users are assigned roles. Users inherit permissions through their assigned roles. | Permissions are determined by the relationships between users and objects. Users are granted access based on their direct or indirect relationships with objects. |
4| Granularity of access control | RBAC typically operates at a coarser level of granularity, with roles representing broad categories of users and permissions. | ReBAC allows for fine-grained access control based on specific relationships between users and objects. Access can be granted based on individual relationships. |
5| Flexibility in modeling complex scenarios | RBAC can struggle to model complex scenarios that don't fit neatly into predefined roles. It may require creating many specialized roles. | ReBAC can easily model complex scenarios by defining relationships between users and objects. It allows for more flexibility in representing real-world access control requirements. |
6| Dynamicity of access control | RBAC is relatively static, as roles and permissions are predefined. Changing access control often requires modifying role definitions or user-role assignments. | ReBAC is more dynamic, as access control is based on relationships that can change over time. Access can be automatically adjusted as relationships evolve, without requiring explicit role or permission changes. |
7| Scalability | RBAC can become complex and difficult to manage as the number of roles and permissions grows. It may lead to role explosion and increased administrative overhead. | ReBAC scales well by focusing on relationships rather than roles. It can handle complex access control scenarios without requiring an excessive number of roles or permissions. |
8| Expressiveness of access control policies | RBAC policies are typically expressed in terms of roles and permissions, which can be limiting in representing complex access control requirements. | ReBAC allows for more expressive access control policies by leveraging relationships between users and objects. It can capture nuanced access control rules based on various relationship types. |
9| Support for contextual access control | RBAC does not inherently consider contextual factors in access control decisions. Additional mechanisms may be needed to incorporate context. | ReBAC can incorporate contextual factors into access control decisions by considering the relationships between users, objects, and other relevant entities. It allows for context-aware access control. |
10| Integration with existing systems | RBAC is widely supported and can be easily integrated into existing systems that are built around roles and permissions. | ReBAC may require more effort to integrate into existing systems, as it introduces a new paradigm based on relationships. However, it can provide more flexibility and fine-grained access control in the long run. |
11| Authorization decisions performance | RBAC authorization decisions are generally faster because permissions are directly derived from roles associated with users. | ReBAC authorization decisions can be slower as they involve evaluating relationships between users and objects, which may require traversing relationships. However, the overhead can be mitigated through optimizations. |
12| Access control administration | RBAC administration involves managing roles, permissions, and user-role assignments. It can be centralized and relatively straightforward. | ReBAC administration involves managing relationships between users and objects. It may require more effort to define and maintain relationships, but it provides greater flexibility in representing access control rules. |