What is a distinctive characteristic of Rule-BAC models?

A distinctive characteristic of Rule-Based Access Control (Rule-BAC) models is their reliance on global rules that dictate access permissions, which apply uniformly across all subjects. This means that instead of assigning permissions on an individual user basis, Rule-BAC utilizes predefined rules that define what permissions are available based on certain criteria or conditions.

In a Rule-BAC model, access decisions are made based on the set rules rather than individual user attributes or roles. This allows for consistent enforcement of security policies across an entire system, promoting a more centralized approach to access control that simplifies management and enhances security by minimizing the risk of human error in permission assignments.

The other options do not accurately represent the defining features of Rule-BAC. For instance, although Rule-BAC can affect user permissions, the emphasis is not on providing flexibility for individual users but rather on adhering to global policies. The requirement for user authentication is also not a unique characteristic of Rule-BAC, as authentication is a standard requirement in all access control models to ensure secure access. Lastly, Rule-BAC is not limited to network access; it can be implemented across various domains, including application access and physical security, thus expanding its applicability beyond just network controls.