Which term describes a mechanism that restricts permissible actions to only allowed actions?

Access control is the term that accurately describes a mechanism designed to restrict permissible actions to only those that are explicitly allowed. This concept is foundational in information security, as it determines who can access resources and what actions they can perform on those resources. Access control mechanisms can include various methodologies, such as role-based access control (RBAC), discretionary access control (DAC), or mandatory access control (MAC), each serving to ensure that users have permissions aligned with their roles and responsibilities.

The essence of access control lies in enforcing policies that define which users or systems can interact with specific parts of a computing environment and under what circumstances. This prevents unauthorized actions, ensuring that resources are protected and only accessed in ways that comply with established security policies.

The other options represent related concepts but do not specifically encapsulate the idea of restricting actions to only those that are allowed. Action limitation suggests a focus on the extent or range of actions but lacks the authoritative aspect of control inherent in access control. Security protocol generally refers to the rules governing secure communication over networks or systems, while permission management indicates the process of defining and managing user permissions, which is a component of access control rather than the overarching mechanism itself.