# ChatGPT Answer ReBAC, short for [[Relationship-Based Access Control]], is a model of access control that determines access rights based on the relationships between the subject and the objects. The relationships can be direct or indirect and can pass through several intermediaries. The relationships can also be dynamic, meaning they change over time as a response to actions performed by users or administrators. RBAC, or Role-Based Access Control, on the other hand, is an approach to restricting system access to authorized users based on their roles within an organization. The roles are based on several factors such as authority, responsibility and competency. Users are only allowed to perform certain tasks that align with their roles. ABAC, or Attribute-Based Access Control, is a model that controls access to objects based on the attributes of the user, the object to be accessed and under certain conditions. Attributes can vary from simple user IDs and file types to more complex ones like user location or project value. The key difference between these models lies in how they define access control: - RBAC focuses on pre-defined job functions (roles), where permissions are assigned based on those roles. - ABAC uses attributes and policies for making decisions about granting access. - ReBAC utilizes relationships between entities for determining access privileges. So while RBAC is best suited for organizations where job functions clearly define who should have access to what (like corporations), ABAC provides more fine-grained control and flexibility (useful in dynamic environments). ReBAC adds another layer of complexity by bringing relationships into consideration – this might be especially useful in social networking scenarios where connections between users can determine what content they have access to. # Gemini Answer ## ReBAC Explained: Relationships Rule Access ReBAC, or Relationship-Based Access Control, is an authorization model that revolves around **relationships** between subjects, resources, and environments to determine access permissions. This differs from other common models like RBAC (Role-Based Access Control) and ABAC (Attribute-Based Access Control) in some key ways: **Core Concept:** - **ReBAC**: Focuses on **relationships** (e.g., ownership, membership, location) to define access control. - **RBAC**: Uses **predefined roles** linked to permissions. - **ABAC**: Utilizes **attributes** (e.g., user role, time of day, resource type) for dynamic access control. **Key Differences:** 2. **Granularity:** - ReBAC provides **finer-grained control** than RBAC by leveraging specific relationships, allowing for more complex authorization scenarios. - ABAC also offers fine-grained control, but ReBAC excels at modeling hierarchical relationships efficiently. 4. **Flexibility:** - ReBAC offers **flexibility** by dynamically evaluating relationships on-demand, leading to adaptable access control. - RBAC can be rigid due to static roles, while ABAC requires defining and managing numerous attributes. 6. **Complexity:** - ReBAC can be **more complex** to implement and manage due to the intricate relationship graph and policy creation. - RBAC is relatively straightforward, while ABAC complexity hinges on the number of attributes and policy logic. **Applications:** - ReBAC is well-suited for systems with complex hierarchies, ownership structures, or dynamic relationships (e.g., healthcare, social networks, government systems). - RBAC works well for simpler systems with well-defined roles and permissions (e.g., internal applications, file systems). - ABAC offers versatility for various scenarios but might require more upfront configuration (e.g., cloud resources, data access control). **Choosing the Right Model:** The optimal model depends on your specific needs: - **Complexity of relationships:** If relationships play a vital role in access control, ReBAC might be ideal. - **Need for flexibility:** If dynamic access based on changing relationships is crucial, ReBAC might be suitable. - **Ease of implementation:** If simplicity and ease of use are priorities, RBAC could be more manageable. Remember, while RBAC and ABAC are distinct models, ReBAC shares characteristics with both. In some cases, it can even be considered a subset of ABAC where relationships act as specific attributes. # References ```dataview Table title as Title, authors as Authors where contains(subject, "ReBAC" ) sort modified desc, authors, title ```